Method for manufacturing semiconductor device, method for processing substrate and substrate processing apparatus

ABSTRACT

There is provided a method for manufacturing a semiconductor device, including forming an insulating film having a prescribed composition and a prescribed film thickness on a substrate by alternately performing the following steps prescribed number of times: supplying one of the sources of a chlorosilane-based source and an aminosilane-based source to a substrate in a processing chamber, and thereafter supplying the other source, to form a first layer containing silicon, nitrogen, and carbon on the substrate; and supplying a reactive gas different from each of the sources, to the substrate in the processing chamber, to modify the first layer and form a second layer.

BACKGROUND

The present application is based on Japanese Patent Applications No.2010-090549 filed on. Apr. 9, 2010, the entire contents of which arehereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a method for manufacturing asemiconductor device including forming a thin film on a substrate, amethod for processing a substrate and a substrate processing apparatus.

DESCRIPTION OF RELATED ART

The step of manufacturing a semiconductor device includes the step offorming a silicon insulating film such as a silicon oxide film (SiO₂)and a silicon nitride film (Si₃N₄) on a wafer such as a silicon wafer.The silicon oxide film has excellent insulation property and lowdielectric property, and is widely used as an insulating film and aninter-layer film. Further, the silicon nitride film has excellentinsulation property, corrosion-resistant property, and film stresscontrollability, etc., and is widely used as the insulating film and amask film, a charge storage film, and a stress control film. A formationmethod includes a chemical vapor deposition (CVD) method and an atomiclayer deposition (ALD) method, etc. When a silicon insulating film isformed by the CVD method and the ALD method, either a chlorosilane-basedsource or an aminosilane-based source is generally used for example, asa silicon source (for example see patent document 1).

PRIOR ART DOCUMENT Patent Documents

-   Patent document 1:-   Japanese Patent Laid Open Publication No. 2001-230248

SUMMARY OF THE INVENTION Problem to be Solved by the Invention

However, when the insulating film is formed particularly in a lowtemperature region, using either the chlorosilane-based source or theaminosilane-based source, reduction of a film quality is observed, likea case that the insulating film with low silicon density is formed.Further, when SiH₄ and Si₂H₆ are used for depositing silicon in aprocess of forming the insulating film, thin film control is carried outby adjusting a wafer temperature and an inner pressure of a processingchamber. However, layered deposition is difficult in this case, andtherefore a deposition method by surface reaction is expected. Note thataccording to an experiment by inventors of the present invention, it isdifficult to deposit silicon at a film formation rate satisfying aproduction efficiency, when the chlorosilane-based source alone is usedand when temperature is set to 550° C. or less. Further, when theaminosilane-based source alone is used, deposition of silicon is notconfirmed at 550° C. or less.

Accordingly, an object of the present invention is to provide a methodfor manufacturing a semiconductor device, a method for processing asubstrate and a substrate processing apparatus, capable of forming ahigh quality insulating film in a low temperature region, when theinsulating film is formed using a chlorosilane-based source and anaminosilane-based source.

Means for Solving the Problem

According to an aspect of the present invention, there is provided amethod for manufacturing a semiconductor device including:

forming an insulating film having a prescribed composition and aprescribed film thickness on substrate by alternately performingfollowing steps prescribed number of times:

supplying one of the sources of a chlorosilane-based source and anaminosilane-based source to a substrate in a processing chamber, andthereafter supplying the other source, to form a first layer containingsilicon, nitrogen, and carbon on the substrate; and

supplying a reactive gas different from each of the sources, to thesubstrate in the processing chamber, to modify the first layer and forma second layer.

According to further other aspect of the present invention, there isprovided a method for processing a substrate, including:

forming an insulating film having a prescribed composition and aprescribed film thickness on a substrate by alternately performing thefollowing steps prescribed number of times:

supplying a chlorosilane-based source and an aminosilane-based source toa substrate in a processing chamber, to form a first layer containingsilicon, nitrogen, and carbon on the substrate; and

supplying a reactive gas different from each of the sources, to thesubstrate in the processing chamber, to modify the first layer and forma second layer.

According to further other aspect of the present invention, there isprovided a method for processing a substrate, including:

forming an insulating film having a prescribed composition and aprescribed film thickness on a substrate by alternately performing thefollowing steps prescribed number of times:

supplying one of the sources of a chlorosilane-based source and anaminosilane-based source to a substrate in a processing chamber, andthereafter supplying the other source, to form a first layer containingsilicon, nitrogen, and carbon on the substrate; and

supplying a reactive gas different from each of the sources, to thesubstrate in the processing chamber, to modify the first layer and forma second layer.

According to further other aspect of the present invention, there isprovided a substrate processing apparatus, including:

a processing chamber in which a substrate is housed;

a first source supply system configured to supply a chlorosilane-basedsource to a substrate in the processing chamber;

a second source supply system configured to supply an aminosilane-basedsource to the substrate in the processing chamber;

a reactive gas supply system configured to supply reactive gas differentfrom each of the sources, to the substrate in the processing chamber;and

a controller configured to control the first source supply system, thesecond source supply system, and the reactive gas supply system, so thatan insulating film having a prescribed composition and a prescribed filmthickness is formed on the substrate by alternately performing thefollowing processes prescribed number of times:

the process of supplying one of the sources of the chlorosilane-basedsource and the aminosilane-based source to the substrate in theprocessing chamber and thereafter supplying the other source, to form afirst layer containing silicon, nitrogen, and carbon on the substrate,and

a process of supplying the reactive gas to the substrate in theprocessing chamber, to modify the first layer and form a second layer.

Advantage of the Invention

According to the present invention, there is provided a method formanufacturing a semiconductor device, a method for processing asubstrate and a substrate processing apparatus, capable of forming anexcellent insulating film in a low temperature region when theinsulating film is formed by using a chlorosilane-based source and anaminosilane-based source.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic block diagram of a vertical processing furnace ofa substrate processing apparatus suitably used in this embodiment,showing a vertical sectional view of a processing furnace portion.

FIG. 2 is a schematic block diagram of the vertical processing furnaceof the substrate processing apparatus suitably used in this embodiment,showing a sectional view of the processing furnace portion taken alongthe line A-A of FIG. 1.

FIG. 3 is a view showing a timing of gas supply and plasma power sourcein a first sequence of this embodiment, wherein (a) shows an example ofa sequence in which film formation is performed by non-plasma, and (b)shows an example of a sequence in which film formation is performedusing plasma.

FIG. 4 is a view showing a timing of the gas supply in a second sequenceof this embodiment.

FIG. 5 is a view showing a timing of gas supply and plasma power sourcein a third sequence of this embodiment, wherein (a) shows an example ofa sequence in which film formation is performed by non-plasma, and (b)shows an example of a sequence in which film formation is performedusing plasma.

FIG. 6 is a view showing a timing of gas supply in a fourth sequence ofthis embodiment.

FIG. 7 is a view showing a timing of gas supply in a fifth sequence ofthis embodiment.

FIG. 8 is a view showing a timing of gas supply in a sixth sequence ofthis embodiment.

FIG. 9 is a view showing a timing of gas supply in a seventh sequence ofthis embodiment.

FIG. 10 is a view showing a timing of gas supply in an eighth sequenceof this embodiment.

FIG. 11 is a view showing a timing of gas supply in a ninth sequence ofthis embodiment.

FIG. 12 is a view showing a timing of gas supply in a tenth sequence ofthis embodiment.

FIG. 13 is a view showing a timing of gas supply in other embodiment.

FIG. 14 is a view showing a timing of gas supply in other embodiment.

FIG. 15 (a) is a graph chart showing a measurement result of XPSspectrum according to example 2 of the present invention, and (b) is agraph chart showing a measurement result of C/Si ratio and N/Si ratioaccording to example 2 of the present invention.

FIG. 16( a) is a graph chart showing a measurement result of XPSspectrum according to example 3 of the present invention, and (b) is agraph chart showing a measurement result of C/Si ratio and N/Si ratioaccording to example 3 of the present invention.

FIG. 17 is a graph chart showing a measurement result of XRF accordingto example 5 of the present invention.

DESCRIPTION OF DETAILED EMBODIMENT OF THE INVENTION

Preferred embodiments of the present invention will be describedhereafter based on the drawings.

FIG. 1 is a schematic block diagram of a vertical processing furnace ofa substrate processing apparatus suitably used in this embodiment,showing a processing furnace 202 portion by a vertical sectional view,and FIG. 2 is a schematic block diagram of the vertical processingfurnace suitably used in this embodiment, showing the processing furnace202 portion by a sectional view taken along the line A-A of FIG. 1.

As shown in FIG. 1, the processing furnace 202 has a heater 207 being aheating unit (heating mechanism). The heater 207 has a cylindricalshape, and is installed on a heater base (not shown) being a holdingplate by being supported thereby. Note that the heater 207 alsofunctions as an activation mechanism for thermally activating gas aswill be describe later.

A reaction tube 203 is disposed inside of the heater 207, so as toconstitute a reaction vessel (processing vessel) concentrically with theheater 207. The reaction tube 203 is made of a heat-resistant materialsuch as quartz (SiO₂) or silicon carbide (SiC), and is formed into acylindrical shape with an upper end closed and a lower end opened. Aprocessing chamber 201 is formed in a cylindrical hollow part of thereaction tube 203, so that wafers 200 being substrates can be housed ina state of being arranged in multiple stages in a horizontal posturevertically by a boat 217 as will be described later.

A first nozzle 249 a, a second nozzle 249 b, a third nozzle 249 c, and afourth nozzle 249 d are provided in the processing chamber 201 so as topass through a lower part of the reaction tube 203. A first gas supplytube 232 a, a second gas supply tube 232 b, a third gas supply tube 232c, and a fourth gas supply tube 232 d are respectively connected to thefirst nozzle 249 a, the second nozzle 249 b, the third nozzle 249 c, andthe fourth nozzle 249 d. Further, a fifth gas supply tube 232 i isconnected to the first gas supply tube 232 a, and a sixth gas supplytube 232 j is connected to a fourth gas supply tube 232 d. Thus, thereaction tube 203 is provided with four nozzles 249 a, 249 b, 249 c, 249d, and six gas supply tubes 232 a, 232 b, 232 c, 232 d, 232 i, 232 j, sothat a plurality of kinds of gases, six kinds here, can be supplied intothe processing chamber 201.

The first gas supply tube 232 a is provided with a mass flow controller(MFC) 241 a being a flow rate control unit (flow rate controller) and avalve 243 a being an open/close valve, sequentially from an upstreamdirection. Further, a fifth gas supply tube 232 i is connected to adownstream side of the valve 243 a of the first gas supply tube 232 a.The fifth gas supply tube 232 i is provided with a mass flow controller241 i being a flow rate control unit (flow rate controller), and a valve243 i being an open/close valve, sequentially from an upstreamdirection. Further, a first inert gas supply tube 232 e is connected tothe downstream side of a connection part connected to the fifth gassupply tube 232 i in the first gas supply tube 232 a. The first inertgas supply tube 232 e is provided with a mass flow controller 241 ebeing a flow rate control unit (flow rate controller), and a valve 243 ebeing an open/close valve sequentially from the upstream direction.Further, the aforementioned first nozzle 249 a is connected to a tip endpart of the first gas supply tube 232 a. The first nozzle 249 a isprovided in an arc-shaped space between an inner wall of the reactiontube 203 and the wafers 200 so as to rise toward an upper part of alamination direction of the wafers 200 extending from a lower part tothe upper part of the inner wall of the reaction tube 203. The firstnozzle 249 a is formed as an L-shaped long nozzle. Gas supply holes 250a for supplying gas are provided on a side face of the first nozzle 249a. The gas supply holes 250 a are opened to face a center of thereaction tube 203. A plurality of gas supply holes 250 a are providedextending from the lower part to the upper part of the reaction tube203, each of them having the same opening area and provided at the sameopening pitch. The first gas supply system is mainly constituted of thefirst gas supply tube 232 a, the mass flow controller 241 a, the valve243 a, and the first nozzle 249 a. Further, the fifth gas supply systemis mainly constituted of the fifth gas supply tube 232 i, the mass flowcontroller 241 i, the valve 243 i, and the first nozzle 249 a. Further,the first inert gas supply system is mainly constituted of the firstinert gas supply tube 232 e, the mass flow controller 241 e, and thevalve 243 e.

The second gas supply tube 232 b is provide with the mass flowcontroller (MFC) 241 b being the flow rate control unit (flow ratecontroller), and a valve 243 b being the open/close valve, sequentiallyfrom the upstream direction. Further, a second inert gas supply tube 232f is connected to the downstream side of the valve 243 b of the secondgas supply tube 232 b. The second inert gas supply tube 232 f isprovided with a mass flow controller 241 f being the flow rate controlunit (flow rate controller), and a valve 243 f being the open/closevalve, sequentially from the upstream direction. Further, theaforementioned second nozzle 249 b is connected to the tip end part ofthe second gas supply tube 232 b. The second nozzle 249 b is provided inthe arc-shaped space between the inner wall of the reaction tube 203 andthe wafers 200 so as to rise toward the upper part of the laminationdirection of the wafers 200, extending from the lower part to the upperpart of the inner wall of the reaction tube 203. The second nozzle 249 bis formed as an L-shaped long nozzle. Gas supply holes 250 b forsupplying gas are provided on the side face of the second nozzle 249 b.The gas supply holes 250 b are opened to face the center of the reactiontube 203. A plurality of gas supply holes 250 b are provided extendingfrom the lower part to the upper part of the reaction tube 203, each ofthem having the same opening area, and provided at the same openingpitch. The second gas supply system is mainly constituted of the secondgas supply tube 232 b, the mass flow controller 241 b, the valve 243 b,and the second nozzle 249 b. Further, the second inert gas supply systemis mainly constituted of the second inert gas supply tube 232 f, themass flow controller 241 f, and the valve 243 f.

The third gas supply tube 232 c is provided with a mass flow controller(MFC) 241C being the flow rate control unit (flow rate controller), anda valve 243 c being the open/close valve, sequentially from the upstreamdirection. Further, a third inert gas supply tube 232 g is connected tothe downstream side of the valve 243 c of the third gas supply tube 232c. The third inert gas supply tube 232 g is provided with a mass flowcontroller 241 g being the flow rate control unit (flow ratecontroller), and a valve 243 g being the open/close valve, sequentiallyfrom the upstream direction. Further, the third nozzle 249 c isconnected to the tip end part of the third gas supply tube 232 c. Thethird nozzle 249 c is provided in an arc-shaped space between the innerwall of the reaction tube 203 and the wafers 200 so as to rise towardthe upper part from the lower part of the inner wall of the reactiontube 203. The first nozzle 249 a is formed as the L-shaped long nozzle.Gas supply holes 250 c for supplying gas are provided on the side faceof the third nozzle 249 a. The gas supply holes 250 a are opened to facethe center of the reaction tube 203. A plurality of gas supply holes 250c are provided extending from the lower part to the upper part of thereaction tube 203, each of them having the same opening area andprovided at the same opening pitch. The third gas supply system ismainly constituted of the first gas supply tube 232 c, the mass flowcontroller 241 c, the valve 243 c, and the third nozzle 249 c. Further,the third inert gas supply system is mainly constituted of the thirdinert gas supply tube 232 g, the mass flow controller 241 g, and thevalve 243 g.

The fourth gas supply tube 232 d is provide with the mass flowcontroller (MFC) 241 d being the flow rate control unit (flow ratecontroller), and a valve 243 d being the open/close valve, sequentiallyfrom the upstream direction. Further, a sixth gas supply tube 232 j isconnected to the downstream side of the valve 243 d of the fourth gassupply tube 232 d. The sixth gas supply tube 232 j is provided with amass flow controller 241 j being the flow rate control unit (flow ratecontroller), and a valve 243 j being the open/close valve sequentiallyfrom the upstream direction. Further, a fourth inert gas supply tube 232h is connected to the downstream side of the connection part to thesixth gas supply tube 232 j in the fourth gas supply tube 232 d. Thefourth inert gas supply tube 232 h is provided with a mass flowcontroller 241 h being the flow rate control unit (flow ratecontroller), and a valve 243 h being the open/close valve sequentiallyfrom the upstream direction. Further, the fourth nozzle 249 d isconnected to the tip end part of the fourth gas supply tube 232 d. Thefourth nozzle 249 d is provided in a buffer chamber 237 being a gasdispersion space.

The buffer chamber 237 is provided along a lamination direction of thewafers 200 extending from the lower part to the upper part of the innerwall of the reaction tube 203 in the arc-shaped space between the innerwall of the reaction tube 203 and the wafers 200. Gas supply holes 250 efor supplying gas, are formed on the end portion of the wall adjacent tothe wafer 200 of the buffer chamber 237. The gas supply holes 250 e areopened to face the center of the reaction tube 203. A plurality of gassupply holes 240 e are provided extending from the lower part to theupper part of the reaction tube 203, each of them having the sameopening area and provided at the same opening pitch.

The first nozzle 249 d is provided on the end portion of an oppositeside to the end portion where the gas supply holes 250 e of the bufferchamber 237 are provided, along the lower part to the upper part of theinner wall of the reaction tube 203, so as to rise toward the upper partin the lamination direction of the wafers 200. The fourth nozzle 249 dis formed as the L-shaped long nozzle. Gas supply holes 250 d forsupplying gas are provided on the side face of the fourth nozzles 249 d.The gas supply holes 250 d are opened to face the center of the bufferchamber 237. Similarly to the gas supply holes 250 e of the bufferchamber 237, a plurality of gas supply holes 250 d are providedextending from the lower part to the upper part of the reaction tube203. Each opening area of the plurality of gas supply holes 250 d may beset to the same opening area and the same opening pitch from theupstream side (lower part) to the downstream side (upper part), when adifferential pressure between the buffer chamber 237 and the processingchamber 201 is small. However, when the differential pressure is large,the opening area may be set to be large and the opening pitch may set tobe small from the upstream side to the downstream side.

In this embodiment, each opening area and opening pitch of each gassupply hole 250 d of the fourth nozzle 249 d is adjusted as describedabove from the downstream side to the upstream side, to thereby ejectapproximately the same flow rate of gas from each gas supply hole 250 d,although there is a difference in flow velocity. Then, the gas ejectedfrom each gas supply hole 250 d is introduced to the inside of thebuffer chamber 237 once, so that a difference in the flow velocity ofthe gas is equalized in the buffer chamber 237.

Namely, the gas ejected into the buffer chamber 237 from each of the gassupply holes 250 d of the fourth nozzle 249 d, is ejected into theprocessing chamber 201 from the gas supply holes 250 e of the bufferchamber 237, after a particle velocity of each gas is relaxed in thebuffer chamber 237. Thus, the gas ejected into the buffer chamber 237from each of the gas supply holes 250 d of the fourth nozzle 249 d,becomes the gas having uniform flow rate and flow velocity, when it isjet into the processing chamber 201 from each of the gas supply holes250 e of the buffer chamber 237.

A fourth gas supply system is mainly constituted of a mass flowcontroller 241 d, a valve 243 d, a fourth nozzle 249 d, and a bufferchamber 237. Further, a sixth gas supply system is mainly constituted ofa sixth gas supply tube 232 j, a mass flow controller 241 j, a valve 243j, a fourth nozzle 249 d, and a buffer chamber 237. Further, a fourthinert gas supply system is mainly constituted of a fourth inert gassupply tube 232 h, a mass flow controller 241 h, and a valve 243 h.

For example, chlorosilane-based source gas being a first silicon sourcegas (first silicon-containing gas) is supplied into the processingchamber 201 from the first gas supply tube 232 a, through the mass flowcontroller 241 a, the valve 243 a, and the first nozzle 249 a. Here, thechlorosilane-based source means a silane source having chloro-groups,which is a source containing at least silicon (Si) and chlorine (Cl).Hexachlorodisilane (Si₂Cl₆, abbreviated as HCD) can be used for exampleas the chlorosilane-based source gas. Note that when a liquid source isused, which is in a liquid state at a normal temperature under a normalpressure like HCD, the liquid source is vaporized by a vaporizationsystem such as a vaporizer and a bubbler, which is then supplied as thesource gas.

The aminosilane-based source gas is supplied into the processing chamber201 for example, through the mass flow controller 241 b, the valve 243b, and the second nozzle 249 b. Here, the aminosilane-based source is asilane source having amine groups (amino groups), which is a sourcecontaining at least silicon (Si), nitrogen (N), and carbon (C).Tris(dimethylamino)silane (Si[N(CH₃)₂]₃H, abbreviated as 3DMAS) gas canbe used as the aminosilane-based source gas. Note that when the liquidsource in the liquid state at a normal temperature under a normalpressure like 3DMAS is used, the liquid source is vaporized by thevaporization system such as a vaporizer and bubbler, which is thensupplied as the source gas.

Boron (B), namely gas containing boron (boron-containing gas) issupplied into the processing chamber 201 through the mass flowcontroller 241 c, the valve 243 c, and the third nozzle 249 c. Borontrichloride (BCl₃) gas can be used for example, as the boron-containinggas.

Gas containing nitrogen (N) (nitrogen-containing gas) for example, issupplied into the processing chamber 201 through the mass flowcontroller 241 d, the valve 243 d, the fourth nozzle 249 d, and thebuffer chamber 237 from the fourth gas supply tube 232 d. Ammonia (NH₃)gas for example, can be used as the nitrogen-containing gas.

For example, gas containing carbon (C) (carbon-containing gas) issupplied into the processing chamber 201 from the fifth gas supply tube232 i through the mass flow controller 241 i, the valve 243 i, the firstgas supply tube 232 a, and the first nozzle 249 a. For example,propylene (C₃H₆) gas can be used as the carbon-containing gas.

For example, gas containing oxygen (O) (oxygen-containing gas) issupplied from the sixth gas supply tube 232 j into the processingchamber 201 through the buffer chamber 237. For example, oxygen (O₂) gascan be used as the oxygen-containing gas.

For example, nitrogen (N₂) gas is supplied into the processing chamber201 from inert gas supply tubes 232 e, 232 f, 232 g, 232 h, through massflow controllers 241 e, 241 f, 241 g, 241 h, valves 243 e, 243 f, 243 g,243 h, gas supply tubes 232 a, 232 b, 232 c, 232 d, gas nozzles 249 a,249 b, 249 c, 249 d, and buffer chamber 237.

Note that when the aforementioned gases are flowed from each gas supplytube for example, a first silicon source gas supply system, namely achlorosilane-based source gas supply system is formed by the first gassupply system. Further, a second silicon source gas supply system,namely an aminosilane-based source gas supply system is formed by thesecond gas supply system. Further, a boron-containing gas supply systemis formed by the third gas supply system. In addition, anitrogen-containing gas supply system is formed by the fourth gas supplysystem. Moreover, a carbon-containing gas supply system is formed by thefifth gas supply system. Further, an oxygen-containing gas supply systemis formed by the sixth gas supply system.

When the chlorosilane-based source gas and the aminosilane-based sourcegas are collectively called a source gas, a source gas supply system isformed by the chlorosilane-based source gas supply system and theaminosilane-based source gas supply system. Note that thechlorosilane-based source gas supply system, the aminosilane-basedsource gas supply system, and the source gas supply system, arerespectively simply called the chlorosilne source supply system, theaminosilane-based source supply system, and the source supply system.Further, when the boron-containing gas, the nitrogen-containing gas, thecarbon-containing gas, and the oxygen-containing gas are collectivelycalled a reactive gas, a reactive gas supply system is formed by theboron-containing gas supply system, the nitrogen-containing gas supplysystem, the carbon-containing gas supply system, and theoxygen-containing gas supply system.

As shown in FIG. 2, a first rod electrode 269 being a first electrode,and a second rod electrode 270 being a second electrode having a longand thin structure respectively, are disposed along the laminationdirection of the wafers 200 extending from the lower part to the upperpart. Each of the first rod electrode 269 and the second rod electrode270 is provided in parallel to the fourth nozzle 249 d. Each of thefirst rod electrode 269 and the second rod electrode 270 is protected bybeing covered with an electrode protective tube 275 being a protectivetube for protecting each electrode, extending from the upper part to thelower part. Either the first rod electrode 269 or the second rodelectrode 270 is connected to a high frequency power source 273 througha matching box 272, and the other one is connected to earth being areference electric potential. As a result, plasma is generated in aplasma generation area between the first rod electrode 269 and thesecond rod electrode 270. A plasma source is formed as a plasmageneration unit (plasma generator), mainly constituted of the first rodelectrode 269, the second rod electrode 270, the electrode protectivetube 275, the matching box 272, and the high frequency power source 273.Note that as will be described later, the plasma source functions as anactivation mechanism for activating the gas by plasma.

The electrode protective tube 275 is configured to insert each of thefirst rod electrode 269 and the second rod electrode 270 into the bufferchamber 237 in a state of being isolated from atmosphere of the bufferchamber 237. Here, when inside of the electrode protective tube 275 isthe same atmosphere as outer air (atmosphere), the first rod electrode269 and the second rod electrode 270 inserted into the electrodeprotective tube 275 respectively, are oxidized by heat of the heater207. Therefore, an inert gas purge mechanism is provided inside of theelectrode protective tube 275, for filling the inside with the inert gasor purging the inside with the inert gas, and suppressing an oxygenconcentration sufficiently low, to thereby prevent oxidation of thefirst rod electrode 269 or the second rod electrode 270.

An exhaust tube 231 for exhausting the atmosphere in the processingchamber 201, is provided in the reaction tube 203. A vacuum pump 246being a vacuum exhaust device is connected to the exhaust tube 231through a pressure sensor 245 being a pressure detection unit (pressuredetector) for detecting a pressure in the processing chamber 201 and anAPC (Auto Pressure Controller) valve 244 being a pressure adjustmentunit (pressure adjuster), so as to vacuum-exhaust the inside of theprocessing chamber 201 to a prescribed pressure (vacuum degree). Notethat the APC valve 244 is an open/close valve capable of performingvacuum-exhaust/stop of vacuum-exhaust of the inside of the processingchamber 201 by opening/closing a valve, and capable of adjusting thepressure by adjusting a degree of the valve. The exhaust system ismainly constituted of the exhaust tube 231, the APC valve 244, thevacuum pump 246, and the pressure sensor 245.

A seal cap 219 being a furnace throat lid member capable of air-tightlyclosing a lower end opening of the reaction tube 203, is provided in alower part of the reaction tube 203. The seal cap 219 is abutted on alower end of the reaction tube 203 from a vertically lower side. Theseal cap 219 is made of metal such as stainless, and is formed into adisc shape. An O-ring 220 being a seal member abutted on the lower endof the reaction tube 203, is provided on an upper surface of the sealcap 219. A rotation mechanism 267 for rotating a boat is installed on anopposite side to the processing chamber 201 of the seal cap 219. Arotary shaft 255 of the rotation mechanism 267 is configured to passthrough the seal cap 219 so as to be connected to a boat 217 as will bedescribed later, to rotate the wafer 200 by rotating the boat 217. Theseal cap 219 is configured to be vertically elevated by a boat elevator115 being an elevation mechanism vertically installed outside of thereaction tube 203, so that the boat 217 can be loaded and unloadedinto/from the processing chamber 201.

The boat 217 being a substrate supporting tool is made of a heatresistant material such as quartz or silicon carbide, and is configuredto support a plurality of wafers 200 in a horizontal posture, arrangedwith centers thereof aligned with each other in multiple stages. Notethat a heat resistant member 218 made of a heat resistant material suchas quartz and silicon carbide is provided in a lower part of the boat217, so that heat from the heater 207 is hardly transmitted to the sealcap 219 side. Note that the heat resistant member 218 may be constitutedof a plurality of heat insulating plates made of the heat resistantmaterial such as quartz and silicon carbide, and a heat insulation plateholder for supporting them in a horizontal posture in multiple stages.

A temperature sensor 263 being a temperature detection unit is installedin the reaction tube 203, so that a temperature inside of the processingchamber 201 has a desired temperature distribution by adjusting a powersupply condition to the heater 207 based on temperature informationdetected by the temperature sensor 263. The temperature sensor 263 isformed into the L-shape similarly to the nozzles 249 a, 249 b, 249 c,and 249 d, and is provided along an inner wall of the reaction tube 203.

A controller 121 being a control part (control unit) is connected tomass flow controllers 241 a, 241 b, 241 c, 241 d, 241 e, 241 f, 241 g,241 h, 241 i, 241 j, valves 243 a, 243 b, 243 c, 243 d, 243 e, 243 f,243 g, 243 h, 243 i, 243 j, the pressure sensor 245, the APC valve 244,the vacuum pump 246, the heater 207, the temperature sensor 263, therotation mechanism 267, the boat elevator 115, the high frequency powersource 273, and the matching box 272, etc. The controller 121 performsflow rate adjustment operation of each kind of gas by mass flowcontrollers 241 a, 241 b, 241 c, 241 d, 241 e, 241 f, 241 g, 241 h, 241i, and 241 j, open/close operation by valves 243 a, 243 b, 243 c, 243 d,243 e, 243 f, 243 g, 243 h, 243 i, and 243 j, pressure adjustmentoperation by open/close of the APC valve 244 based on the pressuresensor 245, temperature adjustment operation by the heater 207 based onthe temperature sensor 263, start and stop of the vacuum pump 246,rotation speed adjustment operation of the rotation mechanism 267,control of an elevation movement of the boat elevator 115, power supplycontrol of the high frequency power source 273, and impedance control bythe matching box 272.

Next, explanation will be given for a sequence example in which aninsulating film is formed on a substrate, as one step of themanufacturing steps of a semiconductor device, using a processingfurnace of the aforementioned substrate processing apparatus. Note thatin the explanation given hereafter, the operation of each partconstituting the substrate processing apparatus, is controlled by thecontroller 121.

In a conventional CVD (Chemical Vapor Deposition) method and ALD (AtomicLayer Deposition) method, for example, in a case of the CVD method, aplurality of kinds of gases containing a plurality of elementsconstituting a film to be formed, are simultaneously supplied, and in acase of the ALD method, a plurality of kinds of gases containing aplurality of elements constituting the film to be formed are alternatelysupplied. Then, the SiO₂ film and the Si₃N₄ film are formed bycontrolling supply conditions such as supply flow rate of the gas,supply time of the gas, and plasma power during supply of the gas. Inthese techniques, for example, when the SiO₂ film is formed, the supplycondition is controlled so that a composition ratio of the film isO/Si≈2 which is a stoichiometric composition, and for example when theSi₃N₄ film is formed, the supply condition is controlled so that thecomposition ratio of the film is N/Si≈1.33 which is the stoichiometriccomposition.

Meanwhile, in the embodiment of the present invention, the supplycondition is controlled so that the composition ratio of the film to beformed is the stoichiometric composition, or is a prescribed compositionratio different from the stoichiometric composition. For example, thesupply condition is controlled so that at least one element of theplurality of elements constituting the film to be formed, is excessiveto the stoichiometric composition more than other element. Explanationwill be given hereafter for the sequence example in which the filmformation is performed while controlling the ratio of the plurality ofelements constituting the film to be formed, namely the compositionratio of the film.

(First Sequence)

First, a first sequence of this embodiment will be described.

FIG. 3 is a view showing a timing of gas supply and plasma power supplyin the first sequence of this embodiment, wherein FIG. 3( a) shows thesequence example in which film formation is performed by non-plasma(without using plasma), and FIG. 3( b) shows the sequence example inwhich film formation is performed using plasma.

In the first sequence of this embodiment, a silicon carbonitride film ora silicon nitride film having a prescribed composition and a prescribedfilm thickness, is formed on the wafer 200 by alternately performing thefollowing steps prescribed number of times:

supplying the chlorosilane-based source to the wafer 200 in theprocessing chamber 201 and thereafter supplying the aminosilane-basedsource thereto, to form a first layer containing silicon, nitrogen, andcarbon on the wafer 200; and

supplying thermally activated or plasma activated nitrogen-containinggas thereto as the reactive gas, to modify the first layer and form asilicon carbonitride layer or form a silicon nitride layer as the secondlayer.

The first sequence of this embodiment will be specifically describedhereafter. Here, explanation will be given for an example of forming thesilicon carbonitride film (SiCN film) or the silicon nitride film (SiNfilm) on the substrate as the insulation film based on the sequence ofFIG. 3, using HCD gas as the chlorosilane-based source gas, and 3DMASgas as the aminosilane-based source gas, and NH₃ gas as thenitrogen-containing gas.

When a plurality of wafers 200 are charged into the boat 217 (wafercharge), as shown in FIG. 1, the boat 217 supporting the plurality ofwafers 200, is lifted by the boat elevator 115, and is loaded into theprocessing chamber 201 (boat load). In this state, the seal cap 219 isset in a state of sealing the lower end of the reaction tube 203 throughthe O-ring 220.

The inside of the processing chamber 201 is vacuum-exhausted by thevacuum pump 246 so that the inside of the processing chamber 201 is setin a desired pressure (vacuum degree). At this time, the pressure in theprocessing chamber 201 is measured by the pressure sensor 245, and basedon the measured pressure information, the APC valve 244 isfeedback-controlled (pressure adjustment). Further, the inside of theprocessing chamber 201 is heated by the heater 207 so as to be a desiredtemperature. At this time, the power supply condition to the heater 207is feedback-controlled based on the temperature information detected bythe temperature sensor 263 (temperature adjustment). Subsequently, thewafer 200 is rotated by rotating the boat 217 by the rotation mechanism267 (wafer rotation). Thereafter, three steps as will be described laterare sequentially executed. [Step 1]

The valve 243 a of the first gas supply tube 232 a is opened, to flowthe HOD gas through the first gas supply tube 232 a. The flow rate ofthe HCD gas flowed through the first gas supply tube 232 a is adjustedby the mass flow controller 241 a. The HOD gas with the flow rateadjusted, is supplied into the processing chamber 201 from the gassupply holes 250 a of the first nozzle 249 a, and is exhausted from theexhaust tube 231. At this time, the HCD gas is supplied to the wafer200. The valve 243 e is simultaneously opened at this time, to flow theinert gas such as N₂ gas through the inert gas supply tube 232 e. Theflow rate of the N₂ gas flowed through the inert gas supply tube 232 eis adjusted by the mass flow controller 241 e. The N₂ gas with the flowrate adjusted, is supplied into the processing chamber 201 together withthe HCD gas, and is exhausted from the exhaust tube 231.

At this time, the pressure in the processing chamber 201 is set in arange of 1 to 13300 Pa for example, and preferably in a rage of 20 to1330 Pa, by properly adjusting the APC valve 244. The supply flow rateof the HCD gas controlled by the mass flow controller 241 a is set in arange of 1 to 1000 sccm for example. The supply flow rate of the N₂ gascontrolled by the mass flow controller 241 e is set in a range of 200 to10000 sccm for example. The supply flow rate of the N₂ gas controlled bythe mass flow controller 241 e is set in a range of 200 to 10000 sccm.The time required for exposing the HCD gas to the wafer 200, namely thegas supply time (irradiation time) is set in a range of 1 to 120 secondsfor example, and preferably set in a range of 1 to 60 seconds. Thetemperature of the heater 207 at this time, is set so that thetemperature of the wafer 200 is in a range of 250 to 700° C. andpreferably in a range of 350 to 600° C. for example. Note that when thetemperature of the wafer 200 is set to less than 250° C., HCD is hardlychemically adsorbed on the wafer 200, and a practical film formationspeed cannot be obtained in some cases. This can be solved by settingthe temperature of the wafer 200 to 250° C. or more. Note that HCD canbe sufficiently adsorbed on the wafer 200 by setting the temperature ofthe wafer 200 to 350° C. or more, and further sufficient film formationspeed can be obtained. Further, when the temperature of the wafer 200exceeds 700° C., CVD reaction is strongly exhibited (vapor phasereaction is dominant), to thereby easily deteriorate the uniformity ofthe film thickness, thus making it difficult to control the filmthickness. The deterioration of the uniformity in the film thickness canbe suppressed by setting the temperature of the wafer in a range of 200to 700° C. or less, thus making it easy to control the film thickness.Particularly, surface reaction is dominant by setting the temperature ofthe wafer 200 to 600° C. or less, thus making it easy to secure theuniformity in the film thickness, thus making it easy to control thefilm thickness. Therefore, the temperature of the wafer 200 ispreferably set in a range of 250 to 700° C. and preferably in a range of350 to 600° C.

The silicon-containing layer of less than 1 atomic layer to severalatomic layers, is formed on a ground film on the surface of the wafer200 by supplying the HCD gas. The silicon-containing layer may be achemical adsorption layer of HCD, or may be a silicon layer (Si layer),or may include both of them. Here, the silicon layer includes not only acontinuous layer made of silicon, but also a discontinuous layer or athin film formed by overlap of them. Note that the discontinuous layermade of silicon is sometimes called the thin film. Further, the chemicaladsorption layer of HCD includes not only a continuous chemicaladsorption layer of HCD molecules, but also a discontinuous chemicaladsorption layer. Note that the layer of less than 1 atomic layer meansthe atomic layer formed discontinuously. When the thickness of thesilicon-containing layer formed on the wafer 200 exceeds several atomiclayers, nitriding action in step 3 as will be described later does notreach an entire body of the silicon-containing layer. Further, a minimumvalue of the silicon-containing layer that can be formed on the wafer200 is less than 1 atomic layer. Therefore, the thickness of thesilicon-containing layer is preferably set to less than 1 atomic layerto several atomic layers. Note that the silicon layer is formed bydeposition of silicon on the wafer 200, and the chemical adsorptionlayer of HCD is formed by chemical adsorption of HCD on the wafer 200.The film formation rate can be increased by forming the silicon layer onthe wafer 200, rather than forming the chemical adsorption layer of HCDon the wafer 200.

After the silicon-containing layer is formed, the valve 243 a is closed,to stop the supply of the HCD gas. At this time, the inside of theprocessing chamber 201 is vacuum-exhausted by the vacuum pump 246, withthe APC valve 244 of the exhaust tube 231 opened, to thereby remove theHCD gas from the processing chamber 201, which is the HCD gas unreactedor after contributing to the reaction remained in the processing chamber201. Note that at this time, supply of the N₂ gas into the processingchamber 201 is maintained, with the valve 243 e opened. Thus, an effectof purging the inside of the processing chamber 201, and removing theHCD gas from the processing chamber 201 is increased, which is the HCDgas unreacted or after contributing to the reaction remained in theprocessing chamber 201.

Not only the HCD gas, but also an inorganic source such astetrachlorosilane (SiCl₄, abbreviated as STC) gas trichlorosilane(SiHCl₃, abbreviated as TCS) gas, dichlorosilane (SiH₂Cl, abbreviated asDCS) gas, monochlorosilane (SiH₃Cl, abbreviated as MCS) gas, etc., maybe used as the chlorosilne source gas. Not only N₂ gas, but also raregas such as Ar gas, He gas, Ne gas, and Xe gas, may be used as the inertgas.

[Step 2]

After residual gas in the processing chamber 201 in the end of step 1,the valve 243 b of the second gas supply tube 232 b is opened, to flow3DMAS gas into the second gas supply tube 232 b. The flow rate of the3DMAS gas flowed into the second gas supply tube 232 b is adjusted bythe mass flow controller 241 b. The 3DMAS gas with the flow rateadjusted, is supplied into the processing chamber 201 from the gassupply holes 250 b of the second nozzle 249 b, and is exhausted from theexhaust tube 231. At this time, the 3DMAS gas is supplied to the wafer200. The valve 243 f is opened simultaneously at this time, to flow theN₂ gas into the inert gas supply tube 232 f. The N₂ gas is supplied intothe processing chamber 201 together with the 3DMAS gas, and is exhaustedfrom the exhaust tube 231.

At this time, the APC valve 244 is properly adjusted, and similarly tostep 1, the pressure in the processing chamber 201 is set in a range of1 to 13300 Pa for example, and preferably in a range of 20 to 1330 Pa.The supply flow rate of the 3DMAS gas controlled by the mass flowcontroller 241 b is set in a range of 1 to 1000 sccm for example. Thesupply flow rate of the N₂ gas controlled by the mass flow controller241 f is set in a range of 200 to 10000 sccm for example. The timerequired for exposing the 3DMAS gas to the wafer 200, namely the gassupply time (irradiation time) is set in a range of 1 to 120 seconds,and preferably in a range of 1 to 60 seconds. Similarly to step 1, thetemperature of the heater 207 at this time, is set so that thetemperature of the wafer 200 is set in a range of 250 to 700° C., andpreferably set in a range of 350 to 600° C.

The silicon-containing layer formed on the wafer 200 in step 1 and the3DMAS gas, are reacted by supply of the 3DMAS gas. Thus, thesilicon-containing layer is modified to the first layer containingsilicon (Si), nitrogen (N), and carbon (C). The first layer becomes thelayer containing Si, N, and C of less than 1 atomic layer to severalatomic layers. Note that the first layer is the layer with relativelylarge ratio of Si component and C component, which is namely the Si-richand C-rich layer.

Thereafter, the valve 243 b of the second gas supply tube 232 b isclosed, to stop the supply of the 3DMAS gas. At this time, the inside ofthe processing chamber 201 is vacuum-exhausted by the vacuum pump 246,with the APC valve 244 of the exhaust tube 231 closed, so that the 3DMASgas unreacted or after contributing to the reaction remained in theprocessing chamber 201 is removed from the processing chamber 201. Notethat the supply of the N₂ gas into the processing chamber 201 ismaintained, with the valve 243 f opened. Thus, the effect of purging theinside of the processing chamber 201, and removing the 3DMAS gas fromthe processing chamber 201 is increased, which is the 3DMAS gasunreacted or after contributing to the reaction remained in theprocessing chamber 201.

Not only the 3DMAS gas, but also an organic source such astetrakis(dimethylamino)silane (Si[N(CH₃)₂]₄, abbreviated as 4DMAS) gas,bis(diethylamino)silane (Si[N(C₂H₅)₂]H₂, abbreviated as 2DEAS) gas,bis(tertiary butyl aminosilane) (SiH₂[NH(C₄H₉)]₂, abbreviated as BTBAS)gas, may be used as the aminosilane-based source gas. Not only the N₂gas, but also the rare gas such as Ar gas, He gas, Ne gas, and Xe gasmay be used as the inert gas.

[Step 3]

After removing the residual gas in the processing chamber 201 in the endof step 2, the valve 243 d of the fourth gas supply tube 232 d isopened, to flow the NH₃ gas into the fourth gas supply tube 232 d. Theflow rate of the NH₃ gas flowed into the fourth gas supply tube 232 d isadjusted by the mass flow controller 241 d. The NH₃ gas with the flowrate adjusted, is supplied into the buffer chamber 237 from the gassupply holes 250 d of the fourth nozzle 249 d. At this time, the NH₃ gassupplied into the buffer chamber 237 is thermally activated by notapplying high frequency power between the first rod electrode 269 andthe second rod electrode 270, and is supplied into the processingchamber 201 from the gas supply holes 250 e, and is exhausted from theexhaust tube 231 (see FIG. 3( a)). Further, at this time, the NH₃ gassupplied into the buffer chamber 237 is plasma-excited by applying thehigh frequency power between the first rod electrodes 269 and the secondrod electrodes 270 via the matching box 272 from the high frequencypower source 273, and is supplied into the processing chamber 201 fromthe gas supply holes 250 e as active species, and is exhausted from theexhaust tube 231 (see FIG. 3( b)). At this time, the thermally or plasmaactivated NH₃ gas is supplied to the wafer 200. The valve 243 h isopened simultaneously at this time, to flow the N₂ gas into the inertgas supply tube 232 h. The N₂ gas is supplied into the processingchamber 201 together with the NH₃ gas, and is exhausted from the exhausttube 231.

When the NH₃ gas is activated by heat and flowed under noplasma-excitation, the APC valve 244 is properly adjusted, to set thepressure in the processing chamber 201 in a range of 50 to 3000 Pa forexample. By setting the pressure in the processing chamber 201 in arelatively high pressure band, the NH₃ gas can be thermally activated bynon-plasma. Note that a soft reaction can be caused by thermallyactivating the NH₃ gas and supplying the thermally activated NH₃ gas,thus making it possible to softly perform nitriding as will be describedlater. Further, when the NH₃ gas is flowed under plasma-excitation asthe active species, the APC valve 244 is properly adjusted, to set thepressure in the processing chamber 201 in a range of 10 to 100 Pa forexample. The supply flow rate of the NH₃ gas controlled by the mass flowcontroller 241 d is set in a range of 100 to 10000 sccm for example. Thesupply flow rate of the N₂ gas controlled by the mass flow controller241 h is set in a range of 200 to 10000 sccm for example. At this time,when the NH₃ gas is thermally activated and flowed, a partial pressureof the NH₃ gas in the processing chamber 201 is set in a range of 6 to2940 Pa for example. Further, when the NH₃ gas is activated by plasmaand flowed, the partial pressure of the NH₃ gas in the processingchamber 201 is set in a range of 6 to 100 Pa for example. The timerequired for exposing the wafer 200 to the thermally activated NH₃ gas,or to the active species obtained by plasma-exciting the NH₃ gas, namelythe gas supply time (irradiation time), is set to 1 to 120 seconds, andpreferably set to 1 to 60 seconds for example. Similarly to steps 1 to2, the temperature of the heater 207 at this time is set so that thetemperature of the wafer is set in a range of 250 to 700° C., and ispreferably in a range of 350 to 600° C. When the NH₃ gas isplasma-excited, the high frequency power applied between the first rodelectrode 269 and the second rod electrode 270 from the high frequencypower source 273, is the power in a range of 50 to 1000 W for example.

The gas flowed through the processing chamber 201 at this time, is theNH₃ gas thermally activated by increasing the pressure in the processingchamber 201, or the active species obtained by plasma-exciting the NH₃gas, and neither the HCD gas nor the 3DMAS gas is flowed through theprocessing chamber 201. Accordingly, the activated NH₃ gas or the NH₃gas turned into the active species, is reacted with at least a part ofthe first layer containing Si, N, and C formed on the wafer 200 in step2, without causing the vapor phase reaction. Thus, the first layer isnitrided, and is modified to the second layer including the siliconcarbonitride layer (SiCN layer), or the silicon nitride layer (SiNlayer).

As shown in FIG. 3( a), the first layer can be modified (changed) to theSiCN layer by thermally activating the NH₃ gas and flowing it into theprocessing chamber 201. At this time, the first layer is modified to theSiCN layer while increasing the ratio of the N-component in the firstlayer. Note that at this time, by a thermally nitriding action of theNH₃ gas, Si—N bond in the first layer is increased and meanwhile Si—Cbond and Si—Si bond are reduced, thus reducing the ratio of C-componentand the ratio of Si-component in the first layer. Namely, the firstlayer can be modified to the SiCN layer while varying the compositionratio in a direction of increasing the nitrogen concentration, and in adirection of reducing the carbon concentration and the siliconconcentration. Further, the ratio of N-component in the SiCN layer,namely the nitrogen concentration can be finely adjusted by controllingprocessing conditions such as the pressure in the processing chamber 201and the gas supply time.

Further, as shown in FIG. 3( b), the first layer can be modified(changed) to the SiCN layer by plasma-nitriding the first layer byflowing the active species obtained by plasma-exciting the NH₃ gas. Atthis time, the first layer can be modified to the SiN layer by makingthe C-component in the first layer desorbed by energy of the activespecies, while increasing the ratio of the N-component in the firstlayer. Note that at this time, by plasma-nitriding action of the NH₃gas, Si—C bond and Si—Si bond are reduced while Si—N bond in the firstlayer is increased, and the ratio of the C-component and the ratio ofthe Si-component in the first layer are reduced. Particularly, theC-component is reduced to an impurity level or substantially disappearsby desorption of its major part. Namely, the first layer can be modifiedto the SiN layer while varying a composition ratio in a direction ofincreasing the nitrogen concentration or in a direction of reducing thecarbon concentration and the silicon concentration. Further, at thistime, the ratio of the N-component in the SiN layer, namely the nitrogenconcentration can be finely adjusted by controlling the processingconditions such as the pressure in the processing chamber 201 and thegas supply time. Thus, the composition ratio of the SiN layer can befurther strictly controlled.

Note that at this time, the nitriding reaction of the first layer ispreferably not to be saturated. For example, when the first layer of 1atomic layer or less than 1 atomic layer is formed in steps 1, 2, a partof the first layer is preferably not to be nitrified. In this case,nitriding is performed under a condition that the nitriding reaction ofthe first layer is unsaturated so that an entire body of the first layerof 1 atomic layer or less than 1 atomic layer is not nitrified.

Note that in order to set the nitriding reaction of the first layer inan unsaturated state, the aforementioned processing condition is used asthe processing condition in step 3, and the nitriding reaction of thefirst layer is easily set in the unsaturated state by using thefollowing processing condition as the processing condition in step 3.

[When the NH₃ Gas is Thermally Activated and Flowed . . . . ]

Wafer temperature: 500 to 600° C.

Pressure in the processing chamber: 133 to 2666 Pa

Partial pressure of the NH₃ gas: 67 to 2394 Pa

NH₃ gas supply flow rate: 1000 to 5000 sccm

N₂ gas supply flow rate: 300 to 1000 sccm

NH₃ gas supply time: 6 to 60 seconds

Thereafter, the valve 243 d of the fourth gas supply tube 232 d isclosed, to stop the supply of the NH₃ gas. At this time, the inside ofthe processing chamber 201 is vacuum-exhausted by the vacuum pump 246,with the APC valve 244 of the exhaust tube 231 opened, so that the NH₃gas unreacted or after contributing to the reaction remained in theprocessing chamber 201 is removed from the processing chamber 201. Notethat at this time, the supply of the N₂ gas into the processing chamber201 is maintained, with the valve 243 h opened. Thus, the effect ofpurging the inside of the processing chamber 201, and removing the NH₃gas from the processing chamber 201 is increased, which is the NH₃ gasunreacted or after contributing to the reaction remained in theprocessing chamber 201.

Gas obtained by burning and plasma-exciting diazin (N₂H₂) gas, hydrazine(N₂H₄) gas, and N₃H₈ gas, etc., may be used, or the gas obtained bydiluting these gases with rare gas such as Ar gas, He gas, Ne gas, andXe gas, which is then thermally or plasma excited, may be used otherthan the gas obtained by thermally exciting or plasma-exciting the NH₃gas.

The aforementioned steps 1 to 3 are set as 1 cycle, and by performingthis cycle one or more number of times (prescribe number of times), thesilicon carbonitride film (SiCN film) or the silicon nitride film (SiNfilm) having a prescribed composition and a prescribed film thicknesscan be formed on the wafer 200. Note that the aforementioned cycle ispreferably repeated multiple number of times.

When film formation processing of forming the SiCN film or the SiN filmhaving a prescribed composition and a prescribed film thickness, isperformed, the inert gas such as N₂ is supplied into the processingchamber 201, and is exhausted from the exhaust tube 231, to therebypurge the inside of the processing chamber 201 with the inert gas (gaspurge). Thereafter, the atmosphere in the processing chamber 201 issubstituted with the inert gas (inert gas substitution), and thepressure in the processing chamber 201 is returned to a normal pressure(returned to the atmosphere).

Thereafter, the seal cap 219 is descended by the boat elevator 115, andthe lower end of the reaction tube 203 is opened, so that the processedwafer 200 is unloaded to the outside of the reaction tube 203 from thelower end of the reaction tube 203 in a state of being supported by theboat 217. Thereafter, the processed wafer 200 is discharged by the boat217 (wafer discharge).

(Second Sequence)

A second sequence of this embodiment will be described next.

FIG. 4 is a view showing a timing of the gas supply in the secondsequence of this embodiment.

In the second sequence of this embodiment, the silicon carbonitride filmhaving a prescribed composition and a prescribed film thickness isformed on the wafer 200 by performing the following steps alternatelyprescribed number of times:

supplying the chlorosilane-based source to the wafer 200 in theprocessing chamber 201, and thereafter supplying the aminosilane-basedsource thereto, to thereby form the first layer on the wafer 200containing silicon, nitrogen, and carbon; and

supplying thermally activated carbon-containing gas to the wafer 200 inthe processing chamber 201 as the reactive gas, to modify the firstlayer, and form the silicon carbonitride layer as the second layer.

The second sequence of this embodiment will be specifically describedhereafter. Here, explanation will be given for a case that the HCD gasis used as the chlorosilane-based source gas, and the 3DMAS gas is usedas the aminosilane-based source gas, and C₃H₆ gas is used as thecarbon-containing gas, to thereby form the silicon carbonitride film(SiCN film) on the substrate as the insulating film, based on thesequence of FIG. 4.

The wafer charge, boat loading, pressure adjustment, temperatureadjustment, and wafer rotation are similarly performed as the firstsequence. Thereafter, three steps as will be described later aresequentially executed.

[Step 1]

Step 1 is performed similarly to the step 1 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 1 are the same as those of the step 1of the first sequence. Namely, in this step, the silicon-containinglayer is formed on the wafer 200 by supplying the HCD gas into theprocessing chamber 201.

[Step 2]

Step 2 is performed similarly to the step 2 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 2 are the same as those of the step 2in the first sequence. Namely, in this step, the silicon-containinglayer and the 3DMAS gas are reacted by supplying the 3DMAS gas into theprocessing chamber 201, to thereby form the first layer containing Si,N, and C.

[Step 3]

After removing the residual gas in the processing chamber 201 in the endof step 2, the valve 243 i of the fifth gas supply tube 232 i is opened,to flow the C₃H₆ gas into the fifth gas supply tube 232 i. The flow rateof the C₃H₆ gas flowed into the fifth gas supply tube 232 i is adjustedby the mass flow controller 241 i. The C₃H₆ gas with the flow rateadjusted, is supplied into the processing chamber 201 from the gassupply holes 250 a of the first nozzle 249 a, and is exhausted from theexhaust tube 231. At this time, the thermally activated C₃H₆ gas issupplied to the wafer 200. The valve 243 e is simultaneously opened atthis time, to flow the N₂ gas into the inert gas supply tube 232 e. TheN₂ gas is supplied into the processing chamber 201 together with theC₃H₆ gas, and is exhausted from the exhaust tube 231.

At this time, the APC valve 244 is properly adjusted, to set thepressure in the processing chamber 201 in a range of 50 to 3000 Pa forexample. The supply flow rate of the C₃H₆ gas controlled by the massflow controller 241 i is set in a range of 100 to 10000 sccm forexample. The supply flow rate of the N₂ gas controlled by the mass flowcontroller 241 e is set in a range of 200 to 10000 sccm for example. Thepartial pressure of the C₃H₆ gas in the processing chamber 201 at thistime, is set in a range of 6 to 2940 Pa. The time required for exposingthe thermally activated C₃H₆ gas to the wafer 200, namely the gas supplytime (irradiation time) is set in a range of 1 to 120 seconds, andpreferably set in a range of 1 to seconds. Similarly to the steps 1 to2, the temperature of the heater 207 at this time is set so that thetemperature of the wafer 200 is in a range of 250 to 700° C., and ispreferably in a range of 350 to 600° C. Note that a soft reaction can becaused by thermally activating the C₃H₆ gas, so that a carbon-containinglayer as will be described later can be easily formed.

The gas flowed into the processing chamber 201 is the thermallyactivated C₃H₆ gas, and neither the HCD gas nor the 3DMAS gas is flowedinto the processing chamber 201. Accordingly, the C₃H₆ gas is suppliedto the wafer 200 in an activated state without causing the vapor phasereaction, and at this time, the carbon-containing layer of less than 1atomic layer, namely a discontinuous carbon-containing layer is formedon the first layer containing Si, N, and C formed on the wafer 200 instep 2. The carbon-containing layer may be a carbon layer (C-layer), andmay be a chemical adsorption layer of C₃H₆, namely the chemicaladsorption layer made of a substance (C_(x)H_(y)) which is adecomposition of C₃H₆. Note that apart of the first layer and the C₃H₆gas are reacted depending on the condition, so that the first layer iscarbonized. Thus, the first layer is modified, to form the second layerincluding the silicon carbonitride layer (SiCN layer).

Note that the C₃H₆ gas is thermally activated and flowed into theprocessing chamber 201, to thereby modify the first layer, and at thistime, the first layer is modified to the SiCN layer while increasing theratio of the C-component in the first layer. Namely, the first layer canbe modified to the SiCN layer while varying the composition ratio in adirection of increasing the carbon concentration. Further, bycontrolling the processing condition such as the pressure in theprocessing chamber 201 and the gas supply time, the ratio of theC-component in the SiCN layer, namely the carbon concentration can befinely adjusted. Thus, the composition ratio of the SiCN layer can bemore strictly controlled.

Thereafter, the valve 243 i of the fifth gas supply tube 232 i isclosed, to stop the supply of the C₃H₆ gas. At this time, the inside ofthe processing chamber 201 is vacuum-exhausted by the vacuum pump 246,with the APC valve 244 of the exhaust tube 231 opened, and the C₃H₆ gasunreacted or after contributing to the reaction remained in theprocessing chamber 201, is removed from the processing chamber 201. Notethat the supply of the N₂ gas into the processing chamber 201 ismaintained, with the valve 243 e opened. Thus, the effect of purging theinside of the processing chamber 201, and removing the C₃H₆ gas from theprocessing chamber 201 is increased, which is the C₃H₆ gas unreacted orafter contributing to the reaction remained in the processing chamber201.

Ethylene (C₂H₄) gas and acetylene (C₂H₂) gas, etc., may be used as thecarbon-containing gas, other than the C₃H₆ gas.

The aforementioned steps 1 to 3 are set as 1 cycle, and by performingthis cycle one or more number of times (prescribe number of times), thesilicon carbonitride film (SiCN film) having a prescribed compositionand a prescribed film thickness can be formed on the wafer 200. Notethat the aforementioned cycle is preferably repeated multiple number oftimes.

When the film formation processing of forming the SiCN film having aprescribed composition and a prescribed film thickness is performed, gaspurge, inert gas substitution, return to the atmosphere, boat unloading,and wafer discharge, are performed similarly to the first sequence.

(Third Sequence)

A third sequence of this embodiment will be described next.

FIG. 5 is a view showing the timing of gas supply and plasma powersupply in the third sequence of this embodiment, wherein FIG. 5( a)shows a sequence example of performing film formation without usingplasma (by non-plasma), and FIG. 5( b) shows a sequence example ofperforming film formation using plasma.

In the third sequence of this embodiment, a silicon oxycarbonitridefilm, a silicon oxide film, or a silicon oxycarbide film having aprescribed composition and a prescribed film thickness is formed on thewafer 200 by performing the following steps alternately prescribednumber of times:

supplying the chlorosilane-based source to the wafer 200 in theprocessing chamber 201, and thereafter supplying the aminosilane-basedsource thereto, to form the first layer on the wafer 200 containingsilicon, nitrogen, and carbon; and

supplying the thermally or plasma activated oxygen-containing gas to thewafer 200 in the processing chamber 201 as the reactive gas, to modifythe first layer and form a silicon oxycarbonitride layer, a siliconoxide layer, or a silicon oxycarbide layer as the second layer.

The third sequence of this embodiment will be more specificallydescribed hereafter. Here, explanation is given for a case that the HCDgas is used as the chlorosilane-based source gas, the 3DMAS gas is usedas the aminosilane-based source gas, and O₂ gas is used asoxygen-containing gas, to thereby form the silicon oxycarbonitride film(SiOCN film), the silicon oxide film (SiO film), or the siliconoxycarbide film (SiOC film) on the substrate as the insulating film.

Processing is performed similarly to the first sequence, regarding thewafer charge, boat loading, pressure adjustment, temperature adjustment,and wafer rotation. Thereafter, three steps as will be described laterare sequentially executed.

[Step 1]

Step 1 is performed similarly to the step 1 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 1 are the same as those of the step 1of the first sequence. Namely, in this step, the silicon-containinglayer is formed on the wafer 200 by supplying the HCD gas into theprocessing chamber 201.

[Step 2]

Step 2 is performed similarly to the step 2 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 2 are the same as those of the step 2of the first sequence. Namely, in this step, the silicon-containinglayer and the 3DMAS gas are reacted by supplying the 3DMAS gas into theprocessing chamber 201, to form the first layer containing Si, N, and C.

[Step 3]

After the residual gas in the processing chamber 201 is removed in theend of the step 2, the valve 243 j of the sixth gas supply tube 232 j isopened, to flow the O₂ gas into the sixth gas supply tube 232 j. Theflow rate of the O₂ gas flowed into the sixth gas supply tube 232 j isadjusted by the mass flow controller 241 j. The O₂ gas with the flowrate adjusted is supplied into the buffer chamber 237 from the gassupply holes 250 d of the fourth nozzle 249 d. At this time, the O₂ gassupplied into the buffer chamber 237 is thermally activated by notapplying high frequency power between the first rod electrode 269 andthe second rod electrode 270, and is supplied into the processingchamber 201 from the gas supply holes 250 e, and is exhausted from theexhaust tube 231 (see FIG. 5( a)). Further, at this time, by applyingthe high frequency power between the first rod electrode 269 and thesecond rod electrode 270 from the high frequency power source 273through the matching box 272, the O₂ gas supplied into the bufferchamber 237 is plasma-excited, and is supplied into the processingchamber 201 from the gas supply holes 250 e as the active species, andis exhausted from the exhaust tube 231 (see FIG. 5( b)). At this time,the thermally or plasma activated O₂ gas is supplied to the wafer 200.The valve 243 h is simultaneously opened at this time, to flow the N₂gas into the inert gas supply tube 232 h. The N₂ gas is supplied intothe processing chamber 201 together with the O₂ gas, and is exhaustedfrom the exhaust tube 231.

When the O₂ gas is thermally activated and flowed without beingplasma-excited, the APC valve 244 is properly adjusted, to set thepressure in the processing chamber 201 in a range of 1 to 3000 Pa forexample. By setting the pressure in the processing chamber 201 in such arelatively high pressure band, the O₂ gas can be thermally activated bynon-plasma. Note that a soft reaction can be caused by thermallyactivating the O₂ gas and supplying the thermally activated O₂ gas, thuscausing a soft oxidation to occur as will be described later. Further,when the O₂ gas is flowed under plasma-excitation as the active species,the APC valve 244 is properly adjusted, to set the pressure in theprocessing chamber 201 in a range of 1 to 100 Pa for example. The supplyflow rate of the O₂ gas controlled by the mass flow controller 241 d isset in a range of 100 to 5000 sccm for example. The supply flow rate ofthe N₂ gas controlled by the mass flow controller 241 h is set in arange of 200 to 10000 sccm for example. At this time, a partial pressureof the O₂ gas in the processing chamber 201 is set in a range of 6 to2940 Pa for example. Further, the time required for exposing the wafer200 to the thermally activated O₂ gas or the active species obtained byplasma-exciting the O₂ gas, namely the gas supply time (irradiationtime) is set in a range of 1 to 120 seconds, and preferably set in arange of 1 to 60 seconds for example. Similarly to the steps 1 to 2, thetemperature of the heater 207 at this time is set so that thetemperature of the wafer 200 is in a range of 250 to 700° C. for exampleand is preferably in a range of 350 to 600° C. When the O₂ gas isplasma-excited, the high frequency power applied between the first rodelectrode 269 and the second rod electrode 270 from the high frequencypower source 273 is set to be the power in a range of 50 to 1000 W forexample.

The gas flowed into the processing chamber 201 at this time, is the O₂gas thermally activated by increasing the pressure in the processingchamber 201, or the active species obtained by plasma-exciting the O₂gas, and neither the HCD gas nor the 3DMAS gas is flowed into theprocessing chamber 201. Accordingly, the O₂ gas activated or turned intothe active species, without causing the vapor phase reaction, is reactedwith at least a part of the first layer containing Si, N, and C formedon the wafer 200 in step 2. Thus, the first layer is oxidized and ismodified to the second layer including the silicon oxycarbonitride layer(SiOCN layer), the silicon oxide layer (SiO layer), or the siliconoxycabide layer (SiOC layer).

As shown in FIG. 5( a), the first layer can be modified (changed) to theSiOCN layer of the SiOC layer by thermally oxidizing the first layer byflowing the thermally activated O₂ gas through the processing chamber201. At this time, the first layer is modified to the SiOCN layer or theSiOC layer while adding the O-component to the first layer. At thistime, by thermally oxidizing action of the O₂ gas, Si—N bond, Si—C bond,and Si—Si bond are reduced, while Si—O bond is increased in the firstlayer, and the ratio of N-component, the ratio of C-component, and theratio of Si-component in the first layer are reduced. At this time, byprolonging the thermally oxidation time or by increasing an oxidizingpower of the thermal oxidation by the O₂ gas, a major part of theN-component is desorbed to reduce the N-component to an impurity level,to achieve a substantial disappearance of the N-component. Namely, thefirst layer can be modified to the SiOCN layer or the SiOC layer whilevarying the composition ratio in a direction of increasing the oxygenconcentration and in a direction of reducing the nitrogen concentration,the carbon concentration, and the silicon concentration. Further, atthis time, the processing conditions such as the pressure in theprocessing chamber 201 and the gas supply time are controlled, so thatthe ratio of the O-component in the SiOCN layer, namely the oxygenconcentration can be finely adjusted. Thus, the composition ratio of theSiOCN layer can be more strictly controlled.

Further, as shown in FIG. 5( b), the active species obtained byplasma-exciting the O₂ gas is flowed into the processing chamber 201, toplasma-oxidize the first layer and modify (change) the first layer tothe SiO layer or the SiOC layer. At this time, the first layer can bemodified to the SiO layer by making both components of the C-componentand the N-component in the first layer desorbed by the energy of theactive species while adding the O-component to the first layer. At thistime, owing to the action of the plasma oxidation by the O₂ gas, Si—Obond in the first layer is increased and meanwhile Si—N bond, Si—C bond,and Si—Si bond are reduced, and the ratio of the N-component in thefirst layer, and the ratio of the C-component and the ratio of theSi-component are reduced. Particularly, a major part of the N-componentand the C-component is desorbed to be reduced to the impurity level, orsubstantially disappears. Namely, the first layer can be modified to theSiO layer while varying the composition ratio in a direction ofincreasing the oxygen concentration or in a direction of reducing thenitrogen concentration, the carbon concentration, and the siliconconcentration. Further, at this time, the N-component in the first layeris desorbed by the energy of the active species and a part of theC-component is remained without being desorbed, to thereby modify thefirst layer to the SiOC layer. At this time, by the action of the plasmaoxidation by the O₂ gas, Si—O bond is increased, and meanwhile Si—Nbond, Si—C bond, and Si—Si bond are reduced in the first layer, and theratio of the N-component, the ratio of the C-component, and the ratio ofthe Si-component in the first layer are reduced. Particularly, a majorpart of the N-component is desorbed to be reduced to the impurity level,or substantially disappears. Namely, the first layer can be modified tothe SiOC layer while varying the composition ratio in a direction ofincreasing the oxygen concentration, or in a direction of reducing thenitrogen concentration, the carbon concentration, and the siliconconcentration.

Note that it is found that the C-component in the first layer formed insteps 1 and 2, is in a rich state compared with the N-component. Forexample, according to a certain experiment, the carbon concentration issometimes about twice or more of the nitrogen concentration. Namely,when the C-component and the N-component in the first layer are desorbedby the energy of the active species, the C-component remains even in astage in which the major part of the N-component is desorbed. Then,oxidation is stopped in this state, to modify the first layer to theSiOC layer. Further, the oxidation is continued even after the end ofthe desorption of the major part of the N-component, and the oxidationis stopped in a stage in which the major part of the C-component isdesorbed, to thereby modify the first layer to the SiO layer.Specifically, the ratio of the C-component, namely the carbonconcentration can be controlled by controlling the gas supply time(oxidation treatment time), and either SiO layer or SiOC layer can beformed while controlling the composition ratio. Further, at this time,the ratio of the O-component in the SiO layer or the SiOC layer, namelythe oxygen concentration can be finely adjusted by controlling theprocessing conditions such as the pressure and the gas supply time inthe processing chamber 201. Thus, the composition ratio of the SiO layeror the SiOC layer can be more strictly controlled.

At this time, an oxidation reaction of the first layer is preferably notto be saturated. For example, when the first layer of 1 atomic layer orless than 1 atomic layer is formed in steps 1 and 2, a part of the firstlayer is preferably oxidized.

In this case, oxidation is performed under a condition that theoxidation reaction of the first layer is unsaturated, so that an entirebody of the first layer of 1 atomic layer or less than 1 atomic layer isnot oxidized.

In order to set the oxidation reaction of the first layer in anunsaturated state, the aforementioned processing condition is used asthe processing condition step 3. In a case of using the followingprocessing condition as the processing condition in step 3, theoxidation reaction of the first layer can be easily unsaturated.

[when the O₂ Gas is Activated and Flowed . . . . ]

Wafer temperature: 500 to 600° C.

Pressure in the processing chamber: 133 to 2666 Pa

Partial pressure of O₂ gas: 67 to 2394 Pa

O₂ gas supply flow rate: 1000 to 5000 sccm

N₂ gas supply flow rate: 300 to 1000 sccm

O₂ gas supply time: 6 to 60 seconds

[when the O₂ Gas is Plasma Activated and Flowed . . . . ]

Wafer temperature: 500 to 600° C.

Pressure in the processing chamber: 33 to 80 Pa

Partial pressure of the O₂ gas: 17 to 67 Pa

O₂ gas supply flow rate: 1000 to 5000 sccm

N₂ gas supply flow rate: 300 to 1000 sccm

O₂ gas supply time: 6 to 60 seconds

Thereafter, the valve 243 j of the sixth gas supply tube 232 j isclosed, to stop the supply of the O₂ gas. At this time, the inside ofthe processing chamber 201 is vacuum-exhausted by the vacuum pump 246,with the APC valve 244 of the exhaust tube 231 opened, and the O₂ gasafter contributing to the reaction remained in the processing chamber201 is removed from the processing chamber 201. Note that the supply ofthe N₂ gas into the processing chamber 201 is maintained, with the valve243 h opened. Thus, the effect of purging the inside of the processingchamber 201, and removing the O₂ gas from the processing chamber 201 isincreased, which is the O₂ gas unreacted or after contributing to thereaction remained in the processing chamber 201.

As the oxygen-containing gas, other than the gas obtained by thermallyor plasma-exciting the O₂ gas, the gas obtained by thermally orplasma-exciting nitrous oxide (N₂O) gas, nitric monoxide (NO) gas,nitrogen dioxide (NO₂) gas, ozone (O₃) gas, hydrogen (H₂) gas+oxygen(O₂) gas, H₂ gas+O₃ gas, steam (H₂O) gas, carbon monoxide (CO) gas,carbon dioxide (CO₂) gas, etc., may be used, or the gas obtained bydiluting these gases with rare gas such as Ar gas, He gas, Ne gas, andXe gas, may be thermally or plasma-excited and used.

The above-described steps 1 to 3 are set as 1 cycle, and this cycle isperformed one or more times (prescribed number of times), to therebyform the silicon oxycarbonitride film (SiOCN film), the silicon oxidefilm (SiO film), or the silicon oxycarbide film (SiOC film) having aprescribed composition and a prescribed film thickness on the wafer 200.Note that the aforementioned cycle is preferably repeated multiplenumber of times.

When the film formation processing is performed, which is the processingof forming the SiOCN film, the SiO film, or the SiOC film having aprescribed composition and a prescribed film thickness, the gas purge,inert gas substitution, return to the atmosphere, boat unloading, andwafer discharge are performed similarly to the first sequence.

(Fourth Sequence)

A fourth sequence of this embodiment will be described next.

FIG. 6 is a view of the timing of the gas supply in the fourth sequenceaccording to this embodiment.

In the fourth sequence of this embodiment, a silicon boron carbonitridefilm is formed by performing the following steps alternately prescribednumber of times:

supplying chlorosilane-based source to the wafer f200 in the processingchamber 201 and thereafter supplying the aminosilane-based sourcethereto as reactive gases, to form a first layer containing silicon,nitrogen, and carbon on the wafer 200; and

supplying thermally activated boron-containing gas to the wafer 200 inthe processing chamber as the reactive gas, to modify the first layerand form a silicon boron carbonitride layer being a second layer.

The fourth sequence of this embodiment will be more specificallydescribed hereafter. Here, explanation will be given for an example offorming a silicon boron carbonitride film (SiBCN film) being theinsulating film on the substrate based on the sequence of FIG. 6, usingthe HCD gas as the chlorosilane-based source gas, and the 3DMAS gas asthe aminosilane-based source gas, and BCl₃ gas as the boron-containinggas.

The wafer charge, boat loading, pressure adjustment, temperatureadjustment, and wafer rotation are similarly performed as the firstsequence. Thereafter, three steps as will be described later aresequentially executed.

[Step 1]

Step 1 is performed similarly to the step 1 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 1 are the same as those of the step 1of the first sequence. Namely, in this step, the silicon-containinglayer is formed on the wafer 200 by supplying the HCD gas into theprocessing chamber 201.

[Step 2]

Step 2 is similarly performed as the step 2 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 2 are the same as those of the step 2of the first sequence. Namely, in this step, the 3DMAS gas is suppliedinto the processing chamber 2 to cause a reaction between thesilicon-containing layer and the 3DMAS gas, to thereby form the firstlayer containing Si, N, and C.

[Step 3]

After the residual gas in the processing chamber 201 is removed in theend of the step 2, the valve 243 c of the third gas supply tube 232 c isopened, to flow the BCl₃ gas into the third gas supply tube 232 c. Theflow rate of the BCl₃ gas flowed into the third gas supply tube 232 c isadjusted by the mass flow controller 241 c. The BCl₃ gas with the flowrate adjusted, is supplied into the processing chamber 201 from the gassupply holes 250 c of the third nozzle 249 c, and is exhausted from theexhaust tube 231. At this time, the thermally activated BCl₃ gas issupplied to the wafer 200. The valve 243 g is simultaneously opened atthis time, to flow the N₂ gas into the inert gas supply tube 232 g. TheN₂ gas is supplied into the processing chamber 201 together with theBCl₃ gas, and is exhausted from the exhaust tube 231.

At this time, the APC valve 244 is properly adjusted, to set thepressure in the processing chamber 201 in a range of 50 to 3000 Pa forexample. The supply flow rate of the BCl₃ gas controlled by the massflow controller 241 c is set in a range of 100 to 10000 sccm forexample. The supply flow rate of the N₂ gas controlled by the mass flowcontroller 241 g is set in a range of 200 to 10000 sccm for example. Thetime required for exposing the BCl₃ gas to the wafer 200, namely the gassupply time (irradiation time) is set in a range of 1 to 120 seconds forexample, and is preferably set in a range of 1 to 60 seconds. Similarlyto the steps 1 to 2, the temperature of the heater 207 at this time isset so that the temperature of the wafer 200 is in a range of 250 to700° C., and is preferably in a range of 350 to 600° C. Note that a softreaction can be caused by supplying the thermally activated BCl₃ gas.Thus, the boron-containing layer as will be described later can beeasily formed.

At this time, the gas flowed into the processing chamber 201 is thethermally activated BCl₃ gas, and neither the HCD gas nor the 3DMAS gasis flowed into the processing chamber 201. Accordingly, the BCl₃ gas issupplied to the wafer 200 in an activated state without causing thevapor phase reaction, and at this time, the boron-containing layer ofless than 1 atomic layer, namely a discontinuous boron-containing layeris formed on the first layer containing Si, N, and C formed on the wafer200 in step 2. The boron-containing layer may be a boron layer (B-layer)or a chemical adsorption layer of BCl₃, which is the chemical adsorptionlayer made of a substance (B_(x)Cl_(y)) which is a decomposition ofBCl₃. Note that a part of the first layer and the BCl₃ gas are reacteddepending on a condition, to boronize the first layer. Thus, the firstlayer is modified to form a second layer including the silicon boroncarbonitride layer (SiBCN layer).

Note that when the BCl₃ gas is thermally activated and is flowed intothe processing chamber 201 to modify the first layer, the first layer ismodified to the SiBCN layer while adding B-component to the first layer.Namely, the first layer can be modified to the SiBCN layer while varyingthe composition ratio in a direction of increasing the boronconcentration. Further, the processing conditions such as the pressurein the processing chamber 201 and the gas supply time are controlled tothereby finely adjust the ratio of the B-component, namely boronconcentration in the SiBCN layer, and the composition ratio of the SiBCNlayer can be further strictly controlled.

Thereafter, the valve 243 c of the third gas supply tube 232 c isclosed, to stop the supply of the BCl₃ gas. At this time, the inside ofthe processing chamber 201 is vacuum-exhausted by the vacuum pump 246,with the APC valve 244 of the exhaust tube 231 opened, to thereby removethe BCl₃ gas unreacted or after contributing to the reaction remained inthe processing chamber 201, from the processing chamber 201. Note thatthe supply of the N₂ gas into the processing chamber 201 is maintained,with the valve 243 g opened. Thus, the effect of purging the inside ofthe processing chamber 201, and removing the BCl₃ gas from theprocessing chamber 201 is increased, which is the BCl₃ gas unreacted orafter contributing to the reaction remained in the processing chamber201.

Diborane (B₂H₆) gas, etc., may be used as the boron-containing gas,other than the BCl₃ gas.

The aforementioned steps 1 to 3 are set as 1 cycle, and by performingthis cycle one or more number of times (prescribe number of times), thesilicon boron carbonitride film (SiBCN film) having a prescribedcomposition and a prescribed film thickness can be formed on the wafer200. Note that the aforementioned cycle is preferably repeated multiplenumber of times.

When the film formation processing of forming the SiBCN film having aprescribed composition and a prescribed film thickness is performed, thegas purge, inert gas substitution, return to the atmosphere, boatunloading, and wafer discharge are performed similarly to the firstsequence.

(Fifth Sequence)

A fifth sequence of this embodiment will be described next.

FIG. 7 is a view showing the timing of the gas supply in the fifthsequence of this embodiment.

In the fifth sequence of this embodiment, a silicon carbonitride film isformed by performing the following steps alternately prescribed numberof times:

supplying the chlorosilane-based source to the wafer 200 in theprocessing chamber 201, and thereafter supplying the aminosilane-basedsource thereto, to form the first layer containing silicon, nitrogen,and carbon on the wafer 200; and

supplying thermally activated carbon-containing gas to the wafer 200 inthe processing chamber 201 as the reactive gas, and thereafter supplyingthermally activated nitrogen-containing gas thereto as the reactive gas,to modify the first layer and form a silicon carbonitride layer as asecond layer.

In forming the second layer, the thermally activated carbon-containinggas is supplied to the wafer 200 in the processing chamber 201, to makethe carbon-containing gas adsorbed on the first layer, and thereafterthe thermally activated nitrogen-containing gas is supplied to the wafer200 in the processing chamber 201 to modify the layer with thecarbon-containing gas chemically adsorbed on the first layer, and formthe silicon carbonitride layer.

The fifth sequence of this embodiment will be more specificallydescribed hereafter. Here, explanation will be given for an example offorming the silicon corbonitride film (SiCN film) being the insulatingfilm on the substrate based on the sequence of FIG. 7, using the HCD gasas the chlorosilane-based source gas, and the 3DMAS gas as theaminosilane-based source gas, and C₃H₆ gas as the carbon-containing gas.

The wafer charge, boat loading, pressure adjustment, temperatureadjustment, and wafer rotation are similarly performed as the firstsequence. Thereafter, four steps as will be described later aresequentially executed.

[Step 1]

Step 1 is performed similarly to the step 1 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 1 are the same as those of the step 1of the first sequence. Namely, in this step, the silicon-containinglayer is formed on the wafer 200 by supplying the HCD gas into theprocessing chamber 201.

[Step 2]

Step 2 is similarly performed as the step 2 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 2 are the same as those of the step 2of the first sequence. Namely, in this step, the 3DMAS gas is suppliedinto the processing chamber 2 to cause a reaction between thesilicon-containing layer and the 3DMAS gas, to thereby form the firstlayer containing Si, N, and C.

[Step 3]

Step 3 is performed similarly to the step 3 of the second sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 3 are the same as those of the step 3of the second sequence.

In step 3, the chemical adsorption layer of C₃H₆, namely the chemicaladsorption layer made of a substance (C_(x)H_(y)) which is adecomposition of C₃H₆ is preferably formed on the first layer containingSi, N, and C formed on the wafer 200 in step 2. Here, the chemicaladsorption layer of C_(x)H_(y) needs to be a discontinuous chemicaladsorption layer of C_(x)H_(y) molecules. Note that when the chemicaladsorption layer of C_(x)H_(y) formed on the first layer is thediscontinuous layer, for example when the discontinuous chemicaladsorption layer of C_(x)H_(y) is formed on the first layer, with anadsorption state on the first layer of C_(x)H_(y) set in a saturationstate, a surface of the first layer is covered with the chemicaladsorption layer of C_(x)H_(y) entirely. In this case, silicon does notexist on the surface of the layer with C_(x)H_(y) chemically adsorbed onthe first layer, thus making it difficult to perform nitriding of thislayer in step 4 as will be described later. This is because althoughnitrogen is bonded to silicon, it is not bonded to carbon. In order tocause a desired nitriding reaction in step 4 as will be described later,the adsorption state on the first layer of CxHy needs to be set in theunsaturated state, which is a state in which silicon is exposed to thesurface of this layer.

In order to set the adsorption state on the first layer of C_(x)H_(y) inthe unsaturated state, the processing conditions in step 3 may be thesame as the processing conditions in the step 3 of the second sequence.However, by using the following processing conditions in step 3, theadsorption state on the first layer of C_(x)H_(y) is easily set in theunsaturated state.

Wafer temperature: 500 to 600° C.

Pressure in the processing chamber: 133 to 2666 Pa

Partial pressure of the C₃H₆ gas: 67 to 2394 Pa

C₃H₆ gas supply flow rate: 1000 to 5000 sccm

N₂ gas supply flow rate: 300 to 1000 sccm

C₃H₆ gas supply time: 6 to 60 seconds

When the C₃H₆ gas is thermally activated and is flowed into theprocessing chamber 201 to make C_(x)H_(y) chemically adsorbed on thefirst layer, the ratio of the C-component in the entire body of thislayer is increased by a chemical adsorption portion of the C_(x)H_(y) onthe first layer. Namely, the composition ratio can be varied in adirection of increasing the carbon concentration.

Further, at this time, the ratio of the C-component in the layer withC_(x)H_(y) chemically adsorbed on the first layer, namely the carbonconcentration can be controlled (finely adjusted) by controlling theprocessing conditions such as the pressure in the processing chamber 201and the gas supply time. Thus, the composition ratio of the SiCN layerformed in step 4 can be more strictly controlled.

[Step 4]

Step 4 is performed similarly to the step 3 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 4 are the same as those of the step 3of the first sequence.

Note that in step 4, the NH₃ gas is thermally activated without beingplasma-excited and is supplied into the processing chamber 201. At thistime, the gas flowed into the processing chamber 201 is the thermallyactivated NH₃ gas, and none of the HCD gas and the 3DMAS gas and theC₃H₆ gas is flowed into the processing chamber 201. Accordingly, the NH₃gas does not cause the vapor phase reaction, and the activated NH₃ gasis reacted with at least a part of the layer with C_(x)H_(y) chemicallyadsorbed on the first layer, which is formed on the wafer 200 in step 3.Thus, this layer is nitrided and is modified to the second layerincluding the silicon carbonitride layer (SiCN layer).

Note that when the NH₃ gas is thermally activated and is flowed into theprocessing chamber 201, to modify the layer with C_(x)H_(y) chemicallyadsorbed on the first layer to the SiCN layer, this layer is modified tothe SiCN layer while increasing the ratio of the N-component in thislayer. At this time, by the thermal nitriding action of the NH₃ gas,Si—N bond in this layer is increased and meanwhile Si—C bond and Si—Sibond are reduced, and the ratio of the C-component and the ratio of theSi-component in this layer are reduced. Namely, the layer withC_(x)H_(y) chemically adsorbed on the first layer can be modified to theSiCN layer while varying the composition ratio in a direction ofincreasing the nitrogen concentration and in a direction of reducing thecarbon concentration and the silicon concentration. Further, theprocessing conditions such as the pressure in the processing chamber 201and the gas supply time are controlled to finely adjust the ratio of theN-component, namely the nitrogen concentration in the SiCN layer. Thus,the composition ratio of the SiCN layer can be more strictly controlled.

At this time, the nitriding reaction of the layer with CxHy chemicallyadsorbed on the first layer is preferably not to be saturated. Namely, apart of the layer is preferably nitrided. In this case, nitriding isperformed under a condition that the nitriding reaction of this layer isunsaturated, so that the entire body of this layer is not nitrided. Notethat in order to make the unsaturated state of the nitriding reaction ofthe layer with C_(x)H_(y) chemically adsorbed on the first layer, theprocessing conditions in step 4 may be the same as the processingconditions in the step 3 of the first sequence.

The aforementioned steps 1 to 4 are set as 1 cycle, and by performingthis cycle one or more number of times (prescribe number of times), thesilicon carbonitride film (SiCN film) having a prescribed compositionand a prescribed film thickness can be formed on the wafer 200. Notethat the aforementioned cycle is preferably repeated multiple number oftimes.

When the film formation processing of forming the SiCN film having aprescribed composition and a prescribed film thickness is performed, thegas purge, inert gas substitution, return to the atmosphere, boatunloading, and wafer discharged are performed similarly to the firstsequence.

(Sixth Sequence)

A sixth sequence of this embodiment will be described next.

FIG. 8 is a view of the timing of the gas supply in the sixth sequenceof this embodiment.

In the sixth sequence of this embodiment, a silicon oxycarbonitride filmhaving a prescribed composition and a prescribed film thickness, isformed on the wafer 200 by alternately performing prescribed number oftimes, supplying the chlorosilne source to the wafer 200 in theprocessing chamber, and thereafter supplying the aminosilane-basedsource thereto, to form the first layer containing silicon, nitrogen,and carbon on the wafer 200; and

supplying the thermally activated carbon-containing gas to the wafer 200in the processing chamber 201 as the reactive gas, and thereaftersupplying the thermally activated oxygen-containing gas thereto as thereactive gas, to modify the first layer and form the siliconoxycarbonitride layer as the second layer.

In forming the second layer, the thermally activated carbon-containinggas is supplied to the wafer 200 in the processing chamber 201, tochemically adsorb the carbon-containing gas on the first layer, andthereafter the thermally activated oxygen-containing gas is supplied tothe wafer 200 in the processing chamber 201, to modify the layer withthe carbon-containing gas chemically adsorbed on the first layer andform the silicon oxycarbonitride layer.

The sixth sequence of this embodiment will be specifically describedhereafter. Here, explanation will be given for a case that the HCD gasis used as the chlorosilane-based source gas, and the 3DMAS gas is usedas the aminosilane-based source gas, C₃H₅ gas is used as thecarbon-containing gas, and the O₂ gas is used as the oxygen-containinggas, to thereby form the silicon oxycarbonitride film (SiOCN film) onthe substrate as the insulating film, based on the sequence of FIG. 8.

The wafer charge, boat loading, pressure adjustment, temperatureadjustment, and wafer rotation are similarly performed as the firstsequence. Thereafter, four steps as will be described later aresequentially executed.

[Step 1]

Step 1 is performed similarly to the step 1 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 1 are the same as those of the step 1of the first sequence. Namely, in this step, the silicon-containinglayer is formed on the wafer 200 by supplying the HCD gas into theprocessing chamber 201.

[Step 2]

Step 2 is performed similarly to the step 2 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 2 are the same as those of the step 2of the first sequence. Namely, in this step, the 3DMAS gas is suppliedinto the processing chamber 201, to cause the reaction between thesilicon-containing layer and the 3DMAS gas, and form the first layercontaining Si, N, and C.

[Step 3]

Step 3 is performed similarly to the step 3 of the fifth sequence.Namely, the processing conditions, the reaction to be caused, the layerto be formed, and a method for controlling the carbon concentration,etc., in step 3 are the same as those of the step 3 of the fifthsequence. Namely, in this step, the C₃H₆ gas is supplied into theprocessing chamber 201, to chemically adsorb the C_(x)H_(y) on the firstlayer.

[Step 4]

Step 4 is performed similarly to the step 3 of the third sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., are the same as those of the step 3 of thethird sequence.

In step 4, the O₂ gas is thermally activated and supplied into theprocessing chamber 201 without being plasma-excited. At this time, thegas flowed into the processing chamber 201 is the thermally activated O₂gas, and neither the HCD gas nor the 3DMAS gas is flowed into theprocessing chamber 201. Accordingly, the O₂ gas does not cause the vaporphase reaction, and the activated O₂ gas is reacted with at least a partof the layer with C_(x)H_(y) chemically adsorbed on the first layer,which is the layer formed on the wafer 200 in step 3. Thus, this layeris oxidized and is modified to the second layer including the siliconoxycarbonitride layer (SiOCN layer).

Note that when the O₂ gas is thermally activated and flowed into theprocessing chamber 201, to thermally oxidize the layer with C_(x)H_(y)chemically adsorbed on the first layer and modify this layer to theSiOCN layer, this layer is modified to the SiOCN layer while adding theO-component to this layer. At this time, by the thermal oxidizing actionby the O₂ gas, Si—O bond is increased and meanwhile Si—N bond, Si—Cbond, and Si—Si bond are reduced in this layer, and the ratio of theN-component, the ratio of the C-component and the ratio of the Sicomponent in this layer are reduced. Namely, the layer with C_(x)H_(y)chemically adsorbed on the first layer can be modified to the SiOCNlayer while varying the composition ratio in a direction of increasingthe oxygen concentration and in a direction of reducing the nitrogenconcentration, the carbon concentration, and the silicon concentration.Further, the processing conditions such as the pressure in theprocessing chamber 201 and the gas supply time are controlled, tothereby finely adjust the ratio of the O-component, namely the oxygenconcentration in the SiOCN layer. Thus, the composition ratio of theSiOCN layer can be more strictly controlled.

At this time, the oxidation reaction of the layer with C_(x)H_(y)chemically adsorbed on the first layer, is preferably not saturated.Namely, a part of this layer is preferably oxidized. In this case,oxidation is performed under a condition that the oxidation reaction ofthis layer is unsaturated, so that the entire body of this layer is notoxidized. Note that in order to set the oxidation reaction of the layerwith C_(x)H_(y) chemically adsorbed on the first layer in theunsaturated state, the processing conditions in step 4 may be the sameas the processing conditions in the step 3 of the third sequence.

The aforementioned steps 1 to 4 are set as 1 cycle, and by performingthis cycle one or more number of times (prescribe number of times), thesilicon carbonitride film (SiCN film) having a prescribed compositionand a prescribed film thickness can be formed on the wafer 200. Notethat the aforementioned cycle is preferably repeated multiple number oftimes.

When the film formation processing of forming the SiOCN film having aprescribed composition and a prescribed film thickness is performed, gaspurge, inert gas substitution, return to the atmosphere, boat unloading,and wafer discharge, are performed similarly to the first sequence.

(Seventh Sequence)

A seventh sequence of this embodiment will be described next.

FIG. 9 is a view of the timing of the gas supply in the seventh sequenceof this embodiment.

In the seventh sequence of this embodiment, a silicon boron carbonitridefilm having a prescribed composition and a prescribed film thickness, isformed on the wafer 200 by alternately performing the following stepsprescribed number of times,

supplying the chlorosilane-based source to the wafer 200 in theprocessing chamber 201, and thereafter supplying the aminosilane-basedsource thereto, to form the first layer containing silicon, nitrogen,and carbon on the wafer 200; and

supplying the thermally activated boron-containing gas to the wafer 200in the processing chamber 201 as the reactive gas, and thereaftersupplying the thermally activated nitrogen-containing gas thereto as thereactive gas, to modify the first layer and form the silicon boroncarbonitride layer as the second layer.

In forming the second layer, the thermally activated boron-containinggas is supplied to the wafer 200 in the processing chamber 201 tochemically adsorb the boron-containing gas on the first layer, andthereafter the thermally activated nitrogen-containing gas is suppliedto the wafer 200 in the processing chamber to modify the layer withboron-containing gas chemically adsorbed on the first layer, and formthe silicon boron carbonitride layer.

The seventh sequence of this embodiment will be more specificallydescribed hereafter. Here, explanation is given for a case that the HCDgas is used as the chlorosilane-based source gas, the 3DMAS gas is usedas the aminosilane-based source gas, the BCl₃ gas is used asboron-containing gas, and the NH₃ gas is used as the nitrogen-containinggas, to form the silicon boron carbonitride film (SiBCN film) on thesubstrate as the insulating film based on the sequence of FIG. 9.

The wafer charge, boat loading, pressure adjustment, temperatureadjustment, and wafer rotation are similarly performed as the firstsequence. Thereafter, four steps as will be described later aresequentially executed.

[Step 1]

Step 1 is performed similarly to the step 1 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 1 are the same as those of the step 1of the first sequence. Namely, in this step, the silicon-containinglayer is formed on the wafer 200 by supplying the HCD gas into theprocessing chamber 201.

[Step 2]

Step 2 is performed similarly to the step 2 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 2 are the same as those of the step 2of the first sequence. Namely, in this step, the silicon-containinglayer and the 3DMAS gas are reacted by supplying the 3DMAS gas into theprocessing chamber 201, to form the first layer containing Si, N, and C.

[Step 3]

Step 3 is performed similarly to the step 3 of the fourth sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 3 are the same as those of the step 3of the fourth sequence.

In step 3, the chemical adsorption layer of BCl₃, namely the chemicaladsorption layer made of a substance (B_(x)Cl_(y)) which is adecomposition of BCl₃ is preferably formed on the first layer containingSi, N, and C formed on the wafer 200 in step 2. Here, boron is bonded tosilicon but is not bonded to carbon, and therefore the chemicaladsorption layer of B_(x)Cl_(y) is a discontinuous chemical adsorptionlayer of B_(x)Cl_(y) molecules.

Note that when the BCl₃ gas is thermally activated and is flowed intothe processing chamber 201, to chemically adsorb the B_(x)Cl_(y) on thefirst layer, the B-component is added by a chemical adsorption portionof the B_(x)Cl_(y) on the first layer. Namely, the composition ratio canbe varied in a direction of increasing the boron concentration. Further,at this time, the processing conditions such as the pressure in theprocessing chamber 201 and the gas supply time are controlled to therebycontrol (finely adjust) the ratio of the B-component in the layer withB_(x)Cl_(y) chemically adsorbed on the first layer, namely control theboron concentration. Thus, the composition ratio of the SiBCN layerformed in step 4 can be more strictly controlled.

[Step 4]

Step 4 is performed similarly to the step 4 of the fifth sequence.Namely, the processing conditions, etc., in step 4 are the same as thoseof the step 4 of the fifth sequence. However, step 4 is slightlydifferent from the step 4 of the fifth sequence, in the reaction to becaused and the layer to be formed.

In step 4, the NH₃ gas is thermally activated and is supplied into theprocessing chamber 201 without being plasma-excited. At this time, thegas flowed into the processing chamber 201 is the thermally activatedNH₃ gas, and none of the HCD gas, 3DMAS gas, and the BCl₃ gas is flowedinto the processing chamber 201. Accordingly, the NH₃ gas does not causethe vapor phase reaction, and the activated NH₃ gas is reacted with atleast a part of the layer with B_(x)Cl_(y) chemically adsorbed on thefirst layer, which is the layer formed on the wafer 200 in step 3. Thus,this layer is nitrided and is modified to the second layer including thesilicon boron carbonitride layer (SiBCN layer).

Note that when the NH₃ gas is thermally activated and is flowed into theprocessing chamber 201, to thermally nitride the layer with BxClychemically adsorbed on the first layer, and modify it to the SiBCNlayer, this layer is modified to the SiBCN layer while increasing theratio of the N-component in this layer. At this time, by the thermalnitriding action of the NH₃ gas, Si—N bond in this layer is increasedand meanwhile Si—B bond, Si—C bond, and Si—Si bond are reduced, and theratio of the B-component, the ratio of the C-component, and the ratio ofthe Si-component in this layer are reduced. Namely, the layer withB_(x)Cl_(y) chemically adsorbed on the first layer can be modified tothe SiBCN layer while varying the composition ratio in a direction ofincreasing the nitrogen concentration, and in a direction of reducingthe boron concentration, the carbon concentration, and the siliconconcentration. Further, at this time, the processing conditions such asthe pressure in the processing chamber 201 and the gas supply time arecontrolled to finely adjust the ratio of the N-component, namely thenitrogen concentration in the SiBCN layer. Thus, the composition ratioof the SiBCN layer can be more strictly controlled.

Note that at this time, the nitriding reaction of the layer withB_(x)Cl_(y) chemically adsorbed on the first layer, is preferably not tobe saturated. Namely, apart of this layer is preferably not to benitrided. In this case, nitriding is performed under a condition thenitriding reaction of this layer is unsaturated so that the entire bodyof this layer is not nitrided. Note that in order to unsaturate thenitriding reaction of the layer with B_(x)Cl_(y) chemically adsorbed onthe first layer, the processing conditions in step 4 may be the same asthe processing conditions in the step 4 of the fifth sequence (step 3 ofthe first sequence).

The aforementioned steps 1 to 4 are set as 1 cycle, and by performingthis cycle one or more number of times (prescribe number of times), thesilicon boron carbonitride film (SiBCN film) having a prescribedcomposition and a prescribed film thickness can be formed on the wafer200. Note that the aforementioned cycle is preferably repeated multiplenumber of times.

When the film formation processing of forming the SiBCN film having aprescribed composition and a prescribed film thickness is performed, thegas purge, inert gas substitution, return to the atmosphere, boatunloading, and wafer discharge, are performed similarly to the firstsequence.

(Eighth Sequence)

An eighth sequence of this embodiment will be described next.

FIG. 10 is a view of the timing of the gas supply in the eighth sequenceof this embodiment.

In the eighth sequence of this embodiment, the silicon oxycarbonitridefilm is formed on the wafer 200 by alternately performing the followingsteps prescribed number of times:

supplying the chlorosilane-based source to the wafer 200 in theprocessing chamber 201, and thereafter supplying the aminosilane-basedsource thereto, to form the first layer containing silicon, nitrogen,and carbon on the wafer 200; and

supplying the thermally activated nitrogen-containing gas as thereactive gas, to the wafer 200 in the processing chamber 201, andthereafter supplying thereto the thermally activated oxygen-containinggas as reactive gases, to modify the first layer and form the siliconoxycarbonitride layer.

Note that in forming the second layer, the thermally activatednitrogen-containing gas is supplied to the wafer 200 in the processingchamber 201, to modify the first layer and form the silicon carbonitridelayer, and thereafter the thermally activated oxygen-containing gas issupplied to the wafer 200 in the processing chamber 201, to modify thesilicon carbonitride layer and form the silicon oxycarbonitride layer.

The eighth sequence of this embodiment will be more specificallydescribed. Here, explanation is given for a case that the HCD gas isused as the chlorosilane-based source gas, the 3DMAS gas is used as theaminosilane-based source gas, the NH₃ gas is used as nitrogen-containinggas, and the O₂ gas is used as the oxygen-containing gas, to therebyform the silicon oxycarbonitride film (SiOCN film) on the substrate asthe insulating film based on the sequence of FIG. 10.

The wafer charge, boat loading, pressure adjustment, temperatureadjustment, and wafer rotation are similarly performed as the firstsequence. Thereafter, four steps as will be described later aresequentially executed.

[Step 1]

Step 1 is performed similarly to the step 1 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 1 are the same as those of the step 1of the first sequence. Namely, in this step, the silicon-containinglayer is formed on the wafer 200 by supplying the HCD gas into theprocessing chamber 201.

[Step 2]

Step 2 is performed similarly to the step 2 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 2 are the same as those of the step 2of the first sequence. Namely, in this step, the silicon-containinglayer and the 3DMAS gas are reacted by supplying the 3DMAS gas into theprocessing chamber 201, to form the first layer containing Si, N, and C.

[Step 3]

Step 3 is performed similarly to the step 3 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 3 are the same as those of the step 3of the first sequence. Note that in this step, the NH₃ gas is thermallyactivated and is flowed into the processing chamber 201 without beingplasma-excited, to modify the first layer to the SiCN layer.

[Step 4]

Step 4 is performed similarly to the step 4 of the sixth sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 4 are the same as those of the step 4of the sixth sequence.

Note that in step 4, the O₂ gas is thermally activated without beingplasma-excited and is supplied into the processing chamber 201. At thistime, the gas flowed into the processing chamber 201 is the thermallyactivated O₂ gas, and none of the HCD gas, 3DMAS gas, and the NH₃ gas isflowed into the processing chamber 201. Accordingly, the O₂ gas does notcause the vapor phase reaction, and the activated O₂ gas is reacted withat least a part of the SiCN layer which is formed on the wafer 200 instep 3. Thus, the SiCN layer is oxidized and is modified to the secondlayer including the silicon oxycarbonitride layer (SiOCN layer).

Note that when the O₂ gas is thermally activated and is flowed into theprocessing chamber 201, to thermally oxidize the SiCN layer and modifyit to the SiOCN layer, the SiCN layer is modified to the SiOCN layerwhile adding the O-component of the SiCN layer. Further, at this time,by the thermal oxidizing action of the O₂ gas, the Si—O bond in the SiCNlayer is increased and meanwhile Si—N bond, Si—C bond, and Si—Si bondare reduced in the SiCN layer, and the ratio of the N-component, theratio of the C-component, and the ratio of the Si-component in the SiCNlayer are reduced. Namely, the SiCN layer and the SiOCN layer can bemodified while varying the composition ratio in a direction ofincreasing the oxygen concentration, and in a direction of reducing thenitrogen concentration, the carbon concentration, and the siliconconcentration. Further, at this time, the ratio of the O-component inthe SiOCN layer, namely the oxygen concentration can be finely adjustedby controlling the processing conditions such as the pressure in theprocessing chamber 201 and the gas supply time. Thus the compositionratio of the SiOCN layer can be more strictly controlled.

In addition, at this time, the oxidizing reaction of the SiCN layer ispreferably not to be saturated. Namely, a part of the SiCN layer ispreferably not to be oxidized. In this case, oxidation is performedunder a condition that the oxidizing reaction of the SiCN layer isunsaturated, so that the entire body of the SiCN layer is not oxidized.Note that in order to set the oxidizing reaction of the SiCN layer inthe unsaturated state, the processing conditions in step 4 may be thesame as the processing conditions in the step 4 of the sixth sequence(step 3 of the third sequence).

The above-described steps 1 to 4 are set as 1 cycle, and this cycle isperformed one or more times (prescribed number of times), to therebyform the silicon oxycarbonitride film (SiOCN film) having a prescribedcomposition and a prescribed film thickness on the wafer 200. Note thatthe aforementioned cycle is preferably repeated multiple number oftimes.

When the film formation processing of forming the SiOCN film having aprescribed composition and a prescribed film thickness is performed, thegas purge, inert gas substitution, return to the atmosphere, boatunloading, and wafer discharge, are performed similarly to the firstsequence.

(Ninth Sequence)

A ninth sequence of this embodiment will be described next.

FIG. 11 is a view of the timing of the gas supply in the ninth sequenceof this embodiment.

In the ninth sequence of this embodiment, a silicon oxycarbonitride filmhaving a prescribed composition and a prescribed film thickness isformed on the wafer 200 by performing the following steps alternatelyprescribed number of times:

supplying the chlorosilane-based source to the wafer 200 in theprocessing chamber 201, and thereafter supplying the aminosilane-basedsource thereto, to form the first layer containing silicon, nitrogen,and carbon on the wafer 200; and

supplying the thermally activated carbon-containing gas to the wafer 200in the processing chamber 201, and thereafter supplying the thermallyactivated nitrogen-containing gas thereto as reactive gases, andthereafter supplying the thermally activated oxygen-containing gas asthe reactive gas, to modify the first layer and form the siliconoxycarbonitride layer as the second layer.

Note that in forming the second layer, the thermally activatedcarbon-containing gas is supplied to the wafer 200 in the processingchamber 201, to make the carbon-containing gas chemically adsorbed onthe first layer, and thereafter the thermally activatednitrogen-containing gas is supplied to the wafer 200 in the processingchamber 201, to modify the layer with the carbon-containing gaschemically adsorbed on the first layer, and form the siliconcarbonitride layer, and thereafter the thermally activatedoxygen-containing gas is supplied to the wafer 200 in the processingchamber 201, to modify the silicon carbonitride layer and form thesilicon oxycarbonitride layer.

The ninth sequence of this embodiment will be more specificallydescribed hereafter. Here, explanation is given for a case that the HCDgas is used as the chlorosilane-based source gas, the 3DMAS gas is usedas the aminosilane-based source gas, and O₂ gas is used asoxygen-containing gas, to form the silicon oxycarbonitride film (SiOCNfilm) on the substrate as the insulating film.

Processing is performed similarly to the first sequence, regarding thewafer charge, boat loading, pressure adjustment, temperature adjustment,and wafer rotation. Thereafter, four steps as will be described laterare sequentially executed.

[Step 1]

Step 1 is performed similarly to the step 1 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 1 are the same as those of the step 1of the first sequence. Namely, in this step, the silicon-containinglayer is formed on the wafer 200 by supplying the HCD gas into theprocessing chamber 201.

[Step 2]

Step 2 is similarly performed as the step 2 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 2 are the same as those of the step 2of the first sequence. Namely, in this step, the 3DMAS gas is suppliedinto the processing chamber 2 to cause a reaction between thesilicon-containing layer and the 3DMAS gas, to form the first layercontaining Si, N, and C.

Step 3 is similarly performed as the step 3 of the fifth sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 3 are the same as those of the step 3of the fifth sequence. Namely, in this step, C₃H₆ gas is supplied intothe processing chamber 201, to make C_(x)H_(y) chemically adsorbed onthe first layer.

Step 4 is similarly performed as the step 4 of the fifth sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 4 are the same as those of the step 4of the fifth sequence. Namely, in this step, the NH₃ gas is suppliedinto the processing chamber 201, so that the layer with C_(x)H_(y)chemically adsorbed on the first layer, is modified to the SiCN layer.

[Step 5]

Step 5 is similarly performed as the step 4 of the eighth sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 5 are the same as those of the step 4of the eighth sequence. Namely, in this step, the O₂ gas is suppliedinto the processing chamber 201, to modify the SiCN layer and form thesecond layer including the SiOCN layer.

The aforementioned steps 1 to 5 are set as 1 cycle, and by performingthis cycle one or more number of times (prescribe number of times), thesilicon oxycarbonitride film (SiOCN film) having a prescribedcomposition and a prescribed film thickness can be formed on the wafer200. Note that the aforementioned cycle is preferably repeated multiplenumber of times.

When the film formation processing of forming the SiOCN film having aprescribed composition and a prescribed film thickness is performed, gaspurge, inert gas substitution, return to the atmosphere, boat unloading,and wafer discharge, are performed similarly to the first sequence.

(Tenth Sequence)

A tenth sequence of this embodiment will be described next.

FIG. 12 is a view of the timing of the gas supply in the tenth sequenceof this embodiment.

In the tenth sequence of this embodiment, the silicon boron carbonitridefilm having a prescribed composition and a prescribed film thickness, isformed on the wafer 200 by alternately performing the following stepsprescribed number of times:

supplying the chlorosilane-based source to the wafer 200 in theprocessing chamber 201, and thereafter supplying the aminosilane-basedsource thereto, to form the first layer containing silicon, nitrogen,and carbon on the wafer 200; and

supplying the thermally activated carbon-containing gas to the wafer 200in the processing chamber 201 as the reactive gas, and thereaftersupplying the boron-containing gas thereto as the reactive gas, andthereafter supplying the thermally activated nitrogen-containing gasthereto as the reactive gas, to modify the first layer and form thesilicon boron carbonitride layer.

Note that in forming the second layer, the thermally activatedcarbon-containing gas is supplied to the wafer 200 in the processingchamber 201, to make the carbon-containing gas chemically adsorbed onthe first layer, and thereafter the thermally activated boron-containinggas is supplied to the wafer 200 in the processing chamber 201, to makethe boron-containing gas further chemically adsorbed on the layer withthe carbon-containing gas chemically adsorbed on the first layer, andthereafter the thermally activated nitrogen-containing gas is suppliedto the wafer 200 in the processing chamber 201, to modify the layer withthe carbon-containing gas and the boron-containing gas chemicallyadsorbed on the first layer, and form the silicon boron carbonitridelayer.

The tenth sequence of this embodiment will be more specificallydescribed hereafter. Here, explanation is given for a case that the HCDgas is used as the chlorosilane-based source gas, the 3DMAS gas is usedas the aminosilane-based source gas, the C₃H₆ gas is used ascarbon-containing gas, the BCl₃ gas is used as the boron-containing gas,and the NH₃ gas is used as the nitrogen-containing gas, to form thesilicon boron carbonitride film (SiBCN film) on the substrate as theinsulating film.

The wafer charge, boat loading, pressure adjustment, temperatureadjustment, and wafer rotation are similarly performed as the firstsequence. Thereafter, four steps as will be described later aresequentially executed.

Step 1 is performed similarly to the step 1 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 1 are the same as those of the step 1of the first sequence. Namely, in this step, the silicon-containinglayer is formed on the wafer 200 by supplying the HCD gas into theprocessing chamber 201.

[Step 2]

Step 2 is performed similarly to the step 2 of the first sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 2 are the same as those of the step 2of the first sequence. Namely, in this step, the 3DMAS gas is suppliedinto the processing chamber 201, to cause a reaction between thesilicon-containing layer and the 3DMAS gas, and form the first layercontaining Si, N, and C.

Step 3 is performed similarly to the step 3 of the fifth sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 3 are the same as those of the step 3of the fifth sequence. Namely, in this step, the C₃H₆ gas is suppliedinto the processing chamber 201, to make the C_(x)H_(y) chemicallyadsorbed on the first layer.

[Step 4]

Step 4 is performed similarly to the step 3 of the seventh sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 4 are the same as those of the step 3of the seventh sequence. Namely, in this step, the BCl₃ gas is suppliedinto the processing chamber 201, to make the B_(x)Cl_(y) chemicallyadsorbed on the layer with C_(x)H_(y) chemically adsorbed on the firstlayer.

[Step 5]

Step 5 is performed similarly to the step 4 of the seventh sequence.Namely, the processing conditions, the reaction to be caused, and thelayer to be formed, etc., in step 4 are the same as those of the step 4of the seventh sequence. Namely, in this step, the NH₃ gas is suppliedinto the processing chamber 201, to modify the layer with C_(x)H_(y) andB_(x)Cl_(y) chemically adsorbed on the first layer, and form the secondlayer including the SiBCN layer.

The aforementioned steps 1 to 5 are set as 1 cycle, and by performingthis cycle one or more number of times (prescribe number of times), thesilicon boron carbonitride film (SiBCN film) having a prescribedcomposition and a prescribed film thickness can be formed on the wafer200. Note that the aforementioned cycle is preferably repeated multiplenumber of times.

When the film formation processing of forming the SiBCN film having aprescribed composition and a prescribed film thickness is performed, thegas purge, inert gas substitution, return to the atmosphere, boatunloading, and wafer discharge, are performed similarly to the firstsequence.

According to this embodiment, when the insulating film is formed usingthe chlorosilane-based source and the aminosilane-based source, thesilicon insulating film having a desired composition with high silicondensity can be formed in a low temperature region. Further, an idealstoichiometric silicon insulating film can be formed. Note thataccording to the inventors of the present invention, it is difficult todeposit silicon on the wafer at a film formation rate of satisfying aproduction efficiency in a temperature zone of 550° C. or less.Moreover, when the aminosilane-based source is used alone, deposition ofthe silicon on the wafer cannot be confirmed in the temperature zone of550° C. or less. However, according to the technique of this embodiment,an excellent silicon insulating film can be formed at the film formationrate of satisfying the production efficiency, even in the lowtemperature zone of 550° C. or less.

Note that when the film formation temperature is lowered, usually,kinetic energy of a molecule is also lowered, thus hardly causing thereaction and desorption of chlorine included in the chlorosilane-basedsource and amine included in the aminosilane-based source, and ligandsof them are remained on the surface of the wafer. Then, such residualligands inhibit the adsorption of the silicon on the surface of thewafer as a steric hindrance, thus lowering the silicon density andcausing deterioration of the film. However, even under a condition thathardly allowing such a reaction/desorption to occur, the residualligands can be desorbed by properly causing the reaction between twosilane sources, namely between the chlorosilane-based source and theaminosilane-based source. Then, the steric hindrance is resolved by thedesorption of the residual ligands, and the silicon can be adsorbed on asite which is opened by the resolution of the steric hindrance, and thesilicon density can be increased. Thus, it can be considered that thefilm with high silicon density can be formed even in the low temperaturezone of 550° C. or less.

Further, according to this embodiment, the chlorosilane-based source issupplied, and thereafter the aminosilane-based source is supplied, toform the first layer containing Si, N, and C, namely the siliconinsulating layer on the wafer, and thereafter the thermally activated orplasma activated nitrogen-containing gas, carbon-containing gas,oxygen-containing gas, or boron-containing gas is supplied to thesubstrate. Therefore, the nitrogen concentration, carbon concentration,oxygen concentration, or boron concentration of the silicon insulatinglayer can be adjusted. Thus, the silicon insulating film having adesired characteristic can be formed by controlling the compositionratio.

Further, by using the silicon insulating film formed by the technique ofthis embodiment as a side wall spacer, a device formation technique withlow leak current and having excellent processability can be provided.

Further, by using the silicon insulating film formed by the technique ofthis embodiment as an etch stopper, the device formation technique withexcellent processability can be provided.

According to this embodiment, an ideal stoichiometric silicon insulatingfilm can be formed without using plasma even in the low temperaturezone. Further, since the silicon insulating film can be formed withoutusing plasma, this embodiment can be applied to a process in which thereis a risk of plasma damage, such as a SAP film of DPT.

Note that in the above-described embodiment, explanation is given for acase that when the first layer containing Si, N, and C is formed in eachsequence, the chlorosilane-based source is supplied to the wafer 200 inthe processing chamber 201, and thereafter the aminosilane-based sourceis supplied to the substrate. However, the sources may be reverselyflowed. Namely, the aminosilane-based source is supplied and thereafterthe chlorosilane-based source may be supplied. Specifically, one of thechlorosilane-based source and the aminosilane-based source is supplied,and thereafter the other source may be supplied. Thus, by changing anorder of flowing the sources, the film quality and the composition ratioof the thin film formed in each sequence can be changed.

Further, by changing not only the order of flowing thechlorosilane-based source and the aminosilane-based source, but also theorder in the flow of all gases including the chlorosilane-based sourceand the aminosilane-based source, the film quality and the compositionratio of the thin film formed in each sequence can be changed.

Further, in the aforementioned embodiment, explanation is given for acase that when the first layer containing Si, N, and C is formed in eachsequence, the chlorosilane-based source and the aminosilane-based sourceare used. However, the silane source having a halogen-based ligand otherthan the chlorosilane-based source may also be used. For example, afluorosilane source can also be used instead of the chlorosilane-basedsource. Here, the fluorosilane source is the silane source having afluoro group, which is a source containing at least silicon (Si) andfluorine (F). Silicon fluoride gas such as silicon tetrafluoride (SiF₄)gas and disilicon hexafluoride (Si₂F₆) gas can be used as thefluorosilane source. In this case, when the first layer containing Si,N, and C is formed in each sequence, the fluorosilane source is suppliedto the wafer 200 in the processing chamber 201, and thereafter theaminosilane-based source is supplied, or the aminosilane-based source issupplied and thereafter the fluorosilane source is supplied.

Further, in the above-described embodiment, explanation is given for acase that plasma is used in step 3 of the first sequence and in step 3of the third sequence. However, plasma may also be used in each step ofother sequence. For example, in each step of each sequence, it is alsoacceptable that the nitrogen-containing gas, the carbon-containing gas,the oxygen-containing gas, and the boron-containing gas areplasma-activated, to modify each layer by plasma-nitriding (nitrogendope), plasma carbonization (carbon dope), plasma oxidation (oxygendope), and plasma boronizing (boron dope). However, use of plasma is notsuitable for the process in which there is a risk of plasma damage, andis preferably applied to other process in which there is no risk ofplasma damage.

Further, in the step of supplying the oxygen-containing gas, thehydrogen-containing gas may be supplied together with theoxygen-containing gas. When the oxygen-containing gas and thehydrogen-containing gas are supplied into the processing chamber 201which is under atmosphere of a pressure of less than the air atmosphere(reduced pressure), the oxygen-containing gas and thehydrogen-containing gas are reacted in the processing chamber 201, togenerate oxidizing species (atomic oxygen, etc.) containing oxygen, andeach layer can be oxidized by this oxidizing species. In this case, eachlayer can be oxidized by a higher oxidizing power than that of a casethat the oxygen-containing gas alone is used for oxidation. Theoxidation treatment is performed under a reduced atmosphere bynon-plasma. Hydrogen (H₂) can be used for example, as thehydrogen-containing gas.

Further, in the above-described embodiment, explanation is given for acase that when the first layer containing Si, N, and C is formed in eachsequence, the chlorosilane-based source is supplied to the wafer 200 inthe processing chamber 201, and thereafter the aminosilane-based sourceis supplied. However, as shown in FIG. 13 and FIG. 14, it is alsoacceptable that the chlorosilane-based source and the aminosilane-basedsource are simultaneously supplied to the wafer 200 in the processingchamber 201, to cause the CVD reaction.

FIG. 13 and FIG. 14 are views of the timing of the gas supply accordingto other embodiment of the present invention, in which thechlorosilane-based source and the aminosilane-based source aresimultaneously supplied. Note that the processing conditions in thiscase may be similar processing conditions as those of each sequence ofthe aforementioned embodiment.

The sequence of FIG. 13 shows an example of forming the siliconoxycarbonitride film (SiOCN film) having a prescribed composition and aprescribed film thickness by alternately performing the following stepsprescribed number of times:

the step of simultaneously supplying the chlorosilane-based source (HCD)and the aminosilane-based source (3DMAS) to the wafer 200 in theprocessing chamber 201, to form the first layer containing silicon,nitrogen, and carbon on the wafer 200; and

the step of supplying the thermally activated carbon-containing gas(C₃H₆) to the wafer 200 in the processing chamber 201 as the reactivegas, and thereafter supplying the thermally activatednitrogen-containing gas (NH₃) as the reactive gas, and thereafter thethermally activated oxygen-containing gas (O₂) as the reactive gas, tomodify the first layer and form the silicon oxycarbonitride layer (SiOCNlayer) as the second layer.

Note that in forming the second layer, the thermally activatedcarbon-containing gas is supplied to the wafer 200 in the processingchamber 201, to make the carbon-containing gas chemically adsorbed onthe first layer, and thereafter the thermally activatednitrogen-containing gas is supplied to the wafer 200 in the processingchamber 201, to modify the layer with the carbon-containing gaschemically adsorbed on the first layer, and thereafter the thermallyactivated oxygen-containing gas is supplied to the wafer 200 in theprocessing chamber 201, to modify the silicon carbonitride layer andform the silicon oxycarbonitride layer.

The sequence of FIG. 14 shows an example of forming the silicon boroncarbonitride film (SiBCN) film having a prescribed composition and aprescribed film thickness by performing the following steps prescribednumber of times:

the step of simultaneously supplying the chlorosilane-based source (HCD)and the aminosilane-based source (3DMAS) to the wafer 200 in theprocessing chamber 201, to form the first layer containing silicon,nitrogen, and carbon on the wafer 200; and

the step of supplying the thermally activated carbon-containing gas(C₃H₆) to the wafer 200 in the processing chamber 201 as the reactivegas, and thereafter supplying the thermally activated boron-containinggas (BCl₃) as the reactive gas, and thereafter supplying the thermallyactivated nitrogen-containing gas (NH₃) as the reactive gas, to modifythe first layer and form the silicon boron carbonitride layer (SiBCNlayer) as the second layer.

In forming the second layer, the thermally activated carbon-containinggas is supplied to the wafer 200 in the processing chamber 201 to makethe carbon-containing gas chemically adsorbed on the first layer, andthereafter the thermally activated boron-containing gas is supplied tothe wafer 200 in the processing chamber 201, to make theboron-containing gas further chemically adsorbed on the layer with thecarbon-containing gas chemically adsorbed on the first layer, andthereafter the thermally activated nitrogen-containing gas is suppliedto the wafer 200 in the processing chamber 201, to modify the layer withthe carbon-containing gas and the boron-containing gas chemicallyadsorbed on the first layer, to form the silicon boron carbonitridelayer.

Thus, the chlorosilane-based source and the aminosilane-based source arenot sequentially supplied to the wafer 200 in the processing chamber201, but simultaneously supplied thereto. Even in such a case, a similaroperation and effect as that of the aforementioned embodiment can beobtained. However, as is shown in the aforementioned embodiment, in acase of a sequential supply of each source, namely in a case ofalternately supplying the chlorosilane-based source and theaminosilane-based source, with purging in the processing chamber 201interposed between them, the chlorosilane-based source and theaminosilane-based source can be properly reacted under a condition of apredominant surface reaction, and controllability of controlling thefilm thickness can be increased.

Incidentally, in a case of a conventional CVD method, a plurality ofkinds of gases including a plurality of elements that constitute thethin film are simultaneously supplied. In this case, in order to controlthe composition ratio of the thin film to be formed, control of a flowrate ratio of the gas supply for supplying gas can be taken intoconsideration for example. In this case, even if controlling supplyconditions such as a substrate temperature, a pressure in the processingchamber, and gas supply time during gas supply, the composition ratio ofthe formed thin film cannot be controlled.

Further, in a case of an ALD method, a plurality of kinds of gasescontaining a plurality of elements that constitute the formed thin film,are alternately supplied. In this case, in order to control thecomposition ratio of the formed thin film, for example control of thegas supply flow rate and the gas supply time during supply of each gascan be considered. Note that in the case of the ALD method, the sourcegas is supplied for the purpose of the adsorption and saturation of thesource gas on the surface of the substrate, and therefore pressurecontrol in the processing chamber is not required. Namely, theadsorption and saturation of the source gas is generated under aprescribed pressure or less that allows the adsorption of the source gasto occur at a reaction temperature. Then, the adsorption and saturationof the source gas can be realized at any pressure value, provided thatthe pressure in the processing chamber is set to a prescribed pressureor less. Therefore, usually when the film formation is performed by theALD method, the pressure in the processing chamber is determineddepending on an exhaustion capability of the substrate processingapparatus, with respect to the gas supply amount. When the pressure inthe processing chamber is varied, chemical adsorption of the source gason the surface of the substrate is probably inhibited, or the reactionin this case is probably almost a CVD reaction, thus making itimpossible to properly perform the film formation by the ALD method.Further, in order to form the thin film having a prescribed filmthickness by the ALD method, the ALD reaction (adsorption andsaturation, surface reaction) is repeatedly performed, and thereforedeposition is insufficient unless each ALD reaction is sufficientlyperformed until each ALD reaction is saturated. In this case, probably asufficient deposition rate cannot be obtained. Therefore, in the case ofthe ALD method, the composition ratio of the thin film is probably notcontrolled by controlling the pressure in the processing chamber.

Meanwhile, in this embodiment, in any one of the sequence, thecomposition ratio of the thin film is controlled (finely adjusted) bycontrolling the pressure in the processing chamber and the gas supplytime in each step. More preferably, the composition ratio of the thinfilm is controlled by controlling the pressure in the processingchamber, or controlling the pressure and the gas supply time.

When the composition ratio of the thin film is controlled by controllingthe pressure in the processing chamber in each step, an influence of adifference in machines in different substrate processing apparatuses canbe reduced. Namely, the composition ratio of the thin film can besimilarly controlled by similar control even in different substrateprocessing apparatuses. In this case, by controlling the gas supply timein each step, the composition ratio of the thin film can be finelyadjusted, and the controllability of controlling the gas supply time canbe increased. In addition, by controlling the pressure in the processingchamber, the composition ratio can be controlled while increasing thefilm formation rate. Namely, by controlling the pressure in theprocessing chamber, the composition ratio of the thin film can becontrolled while increasing the growth rate of the silicon-containinglayer formed in step 1 of each sequence for example. Thus, according tothis embodiment, the composition ratio of the thin film can be similarlycontrolled by similar control, and also the controllability ofcontrolling the composition ratio of the thin film can be increased, andfurther the film formation rate, namely productivity can be improved.

Meanwhile, for example in the film formation by the ALD method, when thecomposition ratio of the thin film is controlled by controlling the gassupply flow rate and the gas supply time in each step, the influence ofthe difference in machines in different substrate processing apparatusesis large. Namely, the composition ratio of the tin film cannot besimilarly controlled even if similar control is performed in thedifferent substrate processing apparatuses. For example, even if the gassupply flow rate and the gas supply time are set to the same flow ratevalue and time in different substrate processing apparatuses, thepressure in the processing chamber is not the same pressure value due tothe difference in machines. Therefore, in this case, the pressure in theprocessing chamber is varied in each substrate processing apparatus, anda desired control of the composition ratio cannot be similarly performedin the different substrate processing apparatuses. Further, the pressurein the processing chamber is varied in each substrate processingapparatus, and therefore chemical adsorption of the source gas on thesurface of the substrate is probably inhibited, or the reaction in thiscase is probably almost a CVD reaction, thus making it impossible toproperly perform the film formation by the ALD method.

EXAMPLES Example 1

Based on the first sequence in the above-described embodiment, the SiCNfilm was formed on the wafer, and the film formation rate and arefractive index of the film (R.I.) were measured. Note that in thisembodiment, the HCD gas was used as the chlorosilane-based source gas,and the 3DMAS gas was used as the aminosilane-based source gas, and theNH₃ gas was used as the nitrogen-containing gas, and the SiCN film wasformed by non-plasma based on the sequence of FIG. 3( a). The processingconditions in each step at this time were set as follows.

(Step 1)

Temperature in the processing chamber: 550° C.

Pressure in the processing chamber: 266 Pa (2 Torr)

HCD gas supply flow rate: 200 sccm

HCD gas irradiation time: 12 seconds

(Step 2)

Temperature in the processing chamber: 550° C.

Pressure in the processing chamber: 266 Pa (2 Torr)

3DMAS gas supply flow rate: 200 sccm

NH₃ gas irradiation time: 12 seconds

(Step 3)

Temperature in the processing chamber: 550° C.

Pressure in the processing chamber: 831 Pa (6.5 Torr)

NH₃ gas supply flow rate: 5000 sccm

NH₃ gas irradiation time: 12 seconds

As a result, the film formation rate of the SiCN film formed in, thisexample was 1.8 Å/cycle, and the refractive index of the film (R.I.) was2.10. Namely, it was found that an excellent silicon insulating filmcould be formed at a film formation rate satisfying the productionefficiency in the low temperature zone of 550° C.

Example 2

The SiCN film was formed on the wafer based on the first sequence in theabove-described embodiment, and the film formation rate and uniformityof the film thickness in-plane of the wafer, and the refractive index(R.I.) were measured. Further, XPS spectrum of the SiCN film wasmeasured, and C—Si ratio of the C-component with respect toSi-component) and N/Si ratio (ratio of the N-component with respect tothe Si-component) were measured. Moreover, step 1 and step 2 of thefirst sequence were alternately repeated, to form a substance containingSi, C, and N (called simply SiCN). Then, the XPS spectrum was measured,and the C/Si ratio and the N/Si ratio were calculated. Note that in thisexample, the HCD gas was used as the chlorosilane-based source gas, andthe 3DMAS gas was used as the aminosilane-based source gas, and the NH₃gas was used as the nitrogen-containing gas. Then, based on the sequenceof FIG. 3( a), the SiCN film was formed by non-plasma. Further, in acomparative example, the HCD gas was used as the chlorosilane-basedsource gas, and the 3DMAS gas was used as the aminosilane-based sourcegas, to form SiCN based on the sequence in which step 1 and step 2 ofthe sequence of FIG. 3( a) are alternately repeated. The processingconditions in each step at this time were set as follows.

(Step 1)

Temperature in the processing chamber: 550° C.

Pressure in the processing chamber: 399 Pa (3 Torr)

HCD gas supply flow rate: 100 sccm

HCD gas irradiation time: 12 seconds

(Step 2)

Temperature in the processing chamber: 550° C.

Pressure in the processing chamber: 10 Pa (1333 Torr)

3DMAS gas supply flow rate: 100 sccm

NH₃ gas irradiation time: 6 seconds

(Step 3)

Temperature in the processing chamber: 550° C.

Pressure in the processing chamber: 865 Pa (6.5 Torr)

NH₃ gas supply flow rate: 4500 sccm

NH₃ gas irradiation time: 24 seconds

As a result, the film formation rate of the SiCN film formed in thisexample was 4.15 Å/cycle, the uniformity in the film thickness in-planeof the wafer was 0.3%, and the refractive index (R.I.) was 2.40. Namely,it was found that an excellent silicon insulating film could be formedat a film formation rate satisfying the production efficiency in the lowtemperature zone of 550° C.

Further as shown in FIG. 15, in the SiCN film formed in this example, itwas found that the ratio of the N-component was increased, and the ratioof the C-component and the ratio of the Si-component were reduced, andthe N-concentration was higher than the C-concentration.

FIG. 15( a) is a graph chart showing a measurement result of the XPSspectrum according to this example, wherein binding energy (eV) is takenon the horizontal axis, and intensity (count/sec) of a photoelectron istaken on the vertical axis respectively. Further, FIG. 15( b) is a graphchart showing the measurement result of the C—Si ratio and the N/Siratio according to this example, wherein the ratio of the C-componentand the N-component with respect to the Si component (arbitrary unit(a.u.)) is taken on the vertical axis. In each figure, “Add. Th—NH₃”shows the measurement result of the SiCN film formed in this example,and “HCD/3DMAS” shows the measurement result of the SiCN formed in thecomparative example. In addition, FIG. 15( b) shows the measurementresult of example 3 (“Add. NH₃ Plasma”) as will be described later, forcomparison.

As shown in FIG. 15( a), it is found that the SiCN formed in thecomparative example is set in C-rich and Si-rich state in which Si—Cbond and Si—Si bond are increased. Meanwhile, in the SiCN film formed inthis example, it is found that Si—N bond is increased, and meanwhileSi—C bond and Si—Si bond are reduced in N-rich state, compared with theSiCN formed in the comparative example. Further, as shown in FIG. 15(b), in the SiCN formed in the comparative example, it is found that C/Siratio is larger than N/Si ratio, and the C-concentration is higher thanthe N-concentration. Meanwhile, it is found that in the SiCN film formedin this example, N/Si ratio is larger than C/Si ratio, and theN-concentration is higher than the C-concentration. Namely, it is foundthat in the SiCN film formed in this example, by a thermal nitridingaction of the NH₃ in step 3, the ratio of the N-component is increased,and the ratio of the C-component and the ratio of the Si-component arereduced, and further the N-concentration is higher than theC-concentration.

Example 3

Based on the first sequence of the above-described embodiment, the SiNfilm is formed on the wafer, and the film formation rate, the uniformityof the film thickness in-plane of the wafer, and the refractive index(R.I.) were measured. Further, in the comparative example, step 1 andstep 2 of the first sequence were alternately repeated to form the SiCN,and the XPS spectrum was measured, and also the C/Si ratio and the N/Siratio were calculated. In this example, the HOD gas was used as thechlorosilane-based source gas, and the 3DMAS gas was used as theaminosilane-based source gas, and the NH₃ gas was used as thenitrogen-containing gas, to form the SiN film using plasma based on thesequence of FIG. 3( b). Meanwhile, in the comparative example, the HCDgas was used as the chlorosilane-based source gas, and the 3DMAS gas wasused as the aminosilane-based source gas, to form the SiCN based on thesequence in which step 1 and step 2 of the sequence of FIG. 3( a) werealternately repeated. The processing conditions in each step at thistime were set as follows.

(Step 1)

Temperature in the processing chamber: 550° C.

Pressure in the processing chamber: 399 Pa (3 Torr)

HCD gas supply flow rate: 200 sccm

HCD gas irradiation time: 12 seconds

(Step 2)

Temperature in the processing chamber: 550° C.

Pressure in the processing chamber: 10 Pa (1333 Torr)

3DMAS gas supply flow rate: 200 sccm

NH₃ gas irradiation time: 6 seconds

(Step 3)

Temperature in the processing chamber: 550° C.

Pressure in the processing chamber: 30 Pa (3999 Torr)

NH₃ gas supply flow rate: 4500 sccm

NH₃ gas irradiation time: 24 seconds

RF power: 300 W

As a result, the film formation rate of the SiN film formed in thisexample was 4.0 Å/cycle, and the uniformity of the film thicknessin-plane of the wafer was 1.7%, and the refractive index of the film(R.I.) was 1.93. Namely, it was found that an excellent siliconinsulating film could be formed at a film formation rate satisfying theproduction efficiency in the low temperature zone of 550° C.

Further, as shown in FIG. 16, in the SiN film formed in this example, itwas found that the ratio of the N-component was remarkably increased,and the ratio of the Si-component was reduced, and further the ratio ofthe C-component was reduced to an impurity level.

FIG. 16( a) is a graph chart showing the measurement result of the XPSspectrum according to this example, wherein the binding energy (eV) istaken on the horizontal axis, and the intensity of the photoelectron(count/sec) is taken on the vertical axis respectively. Further, FIG.16( b) is a graph chart showing the measurement result of the C/Si ratioand the N/Si ratio according to this example, wherein the ratio of theC-component and the N-component with respect to the Si-component(arbitrary unit (a.u.)) is taken on the vertical axis. In each figure,“Add. NH₃ Plasma” shows the measurement result of the SiN film formed inthis example, and “HCD/3DMAS” shows the measurement result of the SiCNformed in the comparative example. In addition, FIG. 16( a) shows themeasurement result of the aforementioned example 2 (“Add. Th—NH₃”), forcomparison.

As shown in FIG. 16( a), it is found that the SiCN formed in thecomparative example is set in C-rich and Si-rich state in which Si—Cbond and Si—Si bond are increased. Meanwhile, in the SiN film formed inthis example, it is found that Si—N bond is increased, and meanwhileSi—C bond and Si—Si bond are remarkably reduced and particularly Si—Cbond is reduced to the impurity level, compared with the SiCN formed inthe comparative example. Further, as shown in FIG. 16( b), in the SiCNformed in the comparative example, it is found that C/Si ratio is largerthan N/Si ratio, and the C-concentration is higher than theN-concentration. Meanwhile, it is found that in the SiN film formed inthis example, N/Si ratio is remarkably larger than C/Si ratio, and theN-concentration is remarkably higher than the C-concentration. Namely,it is found that in the SiN film formed in this example, by a plasmanitriding action of the NH₃ in step 3, the ratio of the N-component isremarkably increased, and the ratio of the Si component is reduced andfurther the ratio of the C-component is remarkably reduced to theimpurity level.

Example 4

Based on the third sequence of the above-described embodiment, the SiOCfilm was formed on the wafer, and the film formation rate, theuniformity of the film thickness in-plane of the wafer, and therefractive index (R.I.) were measured. In this example, the HCD gas wasused as the chlorosilane-based source gas, and the 3DMAS gas was used asthe aminosilane-based source gas, and the N₂O gas was used as theoxygen-containing gas, to form a SiOC film by non-plasma. The processingconditions in each step at this time were set as follows.

(Step 1)

Temperature in the processing chamber: 550° C.

Pressure in the processing chamber: 399 Pa (3 Torr)

HCD gas supply flow rate: 200 sccm

HCD gas irradiation time: 12 seconds

(Step 2)

Temperature in the processing chamber: 550° C.

Pressure in the processing chamber: 10 Pa (1333 Torr)

3DMAS gas supply flow rate: 200 sccm

NH₃ gas irradiation time: 6 seconds

(Step 3)

Temperature in the processing chamber: 550° C.

Pressure in the processing chamber: 10 Pa (1333 Torr)

N₂O gas supply flow rate: 1000 sccm

N₂O gas irradiation time: 30 seconds

As a result, the film formation rate of the SiOC film formed in thisexample was 0.61 Å/cycle, the uniformity in the film thickness in-planeof the wafer was 1.7%, and the refractive index (R.I.) was 1.62. Namely,it was found that an excellent silicon insulating film could be formedat a film formation rate satisfying the production efficiency in the lowtemperature zone of 550° C.

Based on the third sequence of the above-described embodiment, thesupply time of the oxygen-containing gas in step 3 was changed, to formthe SiOCN film or the SiOC was on the wafer, and the O-concentration,C-concentration, and N-concentration of each film formed at this timewere measured by XRF. In this example, the HCD gas was used as thechlorosilane-based source gas, and the 3DMAS gas was used as theaminosilane-based source gas, and the N₂O gas was used as theoxygen-containing gas, to form the SiOCN film or the SiOC film bynon-plasma based on the sequence of FIG. 5( a). The processingconditions in each step at this time were the same as the processingconditions in the aforementioned example 4. However, the N₂O gasirradiation time in step 3 was varied in a range of 1 to 120 seconds.

FIG. 17 is a graph chart showing the measurement result of the XRFaccording to this example, wherein the supply time of the N₂O gas(arbitrary unit (a.u.)) was taken on the horizontal axis, and theO-concentration, C-concentration, and N-concentration (arbitrary unit(a.u.)) are respectively taken on the vertical axis. Symbol  in thefigure indicates the O-concentration in the film, symbol ◯ indicates theC-concentration in the film, and symbol □ in the figure indicates theN-concentration in the film respectively. Further, N₂O flow time=zeroindicates a case that the N₂O gas is not supplied, namely indicates acase that SiCN is formed based on the sequence of FIG. 5( a) in whichstep 1 and step 2 are alternately repeated.

As shown in FIG. 17, in the case of not supplying the N₂O gas(comparative example), it is found that the C-concentration is high, andC-rich SiCN is formed. It is also found that the C-concentration ishigher than the N-concentration. Meanwhile, in a case of supplying theN₂O gas (example), it is found that oxidation occurs by supplying theN₂O gas, so that SiCN is changed to the SiOCN film. It is also foundthat as the supply time of the N₂O gas is prolonged, the oxidation isprogressed to increase the O-concentration, and the C-concentration andthe N-concentration are reduced. It is found that when the supply timeof the N₂O gas is prolonged to some degree and oxidation is progressedto some degree, the N-component is set in the impurity level, and whenthe supply time of the N₂O gas is further prolonged, the oxidation isfurther progressed to achieve substantial disappearance of theN-component, and the SiOC film is formed.

Namely, in this example, it is found that the SiOCN film is formed whileincreasing the ratio of the O-component, and reducing the ratio of theC-component, and further reducing the ratio of the N-component, by thethermal oxidizing action of the N₂O gas in step 3. It is also found thatby the thermal oxidizing action of the N₂O gas in step 3, the SiOC filmis formed while increasing the ratio of the O-component and reducing theratio of the C-component, and further reducing the ratio of theN-component to the impurity level (or the N-component disappearssubstantially).

Preferred aspects of the present invention will be supplementarilydescribed hereafter.

According to an aspect of the present invention, there is provided amethod for manufacturing a semiconductor device, including:

forming an insulating film having a prescribed composition and aprescribed film thickness on a substrate by alternately performingfollowing steps prescribed number of times:

supplying one of the sources of a chlorosilane-based source and anaminosilane-based source to a substrate in a processing chamber, andthereafter supplying the other source, to form a first layer containingsilicon, nitrogen, and carbon on the substrate; and

supplying a reactive gas different from each of the sources, to thesubstrate in the processing chamber, to modify the first layer and forma second layer.

Preferably, in forming the second layer, thermally or plasma activatednitrogen-containing gas is supplied to the substrate as the reactivegas, to form a silicon carbonitride layer or a silicon nitride layer asthe second layer, and

in forming the insulating film, a silicon carbonitride film or a siliconnitride film is formed as the insulating film.

Further preferably, in forming the second layer, thermally activatednitrogen-containing gas is supplied to the substrate as the reactivegas, to form a silicon carbonitride layer as the second layer, and

in forming the insulating film, a silicon carbonitride film is formed asthe insulating film.

Further preferably, in forming the second layer, plasma activatednitrogen-containing gas is supplied to the substrate as the reactivegas, to form a silicon nitride layer as the second layer, and

in forming the insulating film, a silicon nitride film is formed as theinsulating film.

Further preferably, in forming the second layer, thermally activatedcarbon-containing gas is supplied to the substrate as the reactive gas,to form a silicon carbonitride layer as the second layer, and

in forming the insulating film, a silicon carbonitride film is formed asthe insulating film.

Further preferably, in forming the second layer, thermally orplasma-activated oxygen-containing gas is supplied to the substrate asthe reactive gas, to form a silicon oxycarbonitride layer, a siliconoxycarbide layer or a silicon oxide layer as the second layer, and

in forming the insulating film, a silicon oxycarbonitride film, asilicon oxycarbide film, or a silicon oxide film is formed as theinsulating film.

Further preferably, in forming the second layer, thermally activatedoxygen-containing gas is supplied to the substrate as the reactive gas,to form a silicon oxycarbonitride layer or a silicon oxycarbide layer asthe second layer, and

in forming the insulating film, a silicon oxycarbonitride film or asilicon oxycarbide film is formed as the insulating film.

Further preferably, in forming the second layer, thermally activatedoxygen-containing gas is supplied to the substrate as the reactive gas,to form a silicon oxide layer or a silicon oxycarbide layer as thesecond layer, and

in forming the insulating film, a silicon oxide film or a siliconoxycarbide film is formed as the insulating film.

Further preferably, in forming the second layer, thermally activatedboron-containing gas is supplied to the substrate as the reactive gas,to form a silicon boron carbonitride layer as the second layer, and

in forming the insulating film, a silicon boron carbonitride film isformed as the insulating film.

Further preferably, in forming the second layer, thermally activatedcarbon-containing gas is supplied to the substrate as the reactive gas,and thereafter thermally activated nitrogen-containing gas is suppliedto the substrate as the reactive gas, to form a silicon carbonitridelayer as the second layer, and

in forming the insulating film, a silicon carbonitride film is formed asthe insulating film.

Further preferably, in forming the second layer, thermally activatedcarbon-containing gas is supplied to the substrate as the reactive gas,and thereafter thermally activated oxygen-containing gas is supplied tothe substrate as the reactive gas, to form a silicon oxycarbonitridelayer as the second layer, and

in forming the insulating film, a silicon oxycarbonitride film is formedas the insulating film.

Further preferably, in forming the second layer, thermally activatedboron-containing gas is supplied to the substrate as the reactive gas,and thereafter thermally activated nitrogen-containing gas is suppliedto the substrate as the reactive gas, to form a silicon boroncarbonitride layer as the second layer, and

in forming the insulating film, a silicon boron carbonitride film isformed as the insulating film.

Further preferably, in forming the second layer, thermally activatednitrogen-containing gas is supplied to the substrate as the reactivegas, and thereafter thermally activated oxygen-containing gas issupplied to the substrate as the reactive gas, to form a siliconoxycarbonitride layer as the second layer, and

in forming the insulating film, a silicon oxycarbonitride film is formedas the insulating film.

Further preferably, in forming the second layer, thermally activatedcarbon-containing gas is supplied to the substrate as the reactive gas,and thereafter thermally activated nitrogen-containing gas is suppliedto the substrate as the reactive gas, and thereafter thermally activatedoxygen-containing gas is supplied to the substrate as the reactive gas,to form a silicon oxycarbonitride layer as the second layer, and

in forming the insulating film, a silicon oxycarbonitride film is formedas the insulating film.

Further preferably, in forming the second layer, thermally activatedcarbon-containing gas is supplied to the substrate as the reactive gas,and thereafter thermally activated boron-containing gas is supplied tothe substrate as the reactive gas, and thereafter thermally activatednitrogen-containing gas is supplied to the substrate as the reactivegas, to form a silicon boron carbonitride layer as the second layer, and

in forming the insulating film, a silicon boron carbonitride film isformed as the insulating film.

According to other aspect of the present invention, there is provided amethod for manufacturing a semiconductor device including:

forming an insulating film having a prescribed composition and aprescribed film thickness on a substrate by alternately performingfollowing steps prescribed number of times:

supplying a chlorosilane-based source and an aminosilane-based source tothe substrate in a processing chamber, to form a first layer containingsilicon, nitrogen, and carbon on the substrate; and

supplying a different reactive gas from each of the sources, to thesubstrate in the processing chamber, to modify the first layer and forma second layer.

According to further other aspect of the present invention, there isprovided a method for processing a substrate including:

forming an insulating film having a prescribed composition and aprescribed film thickness on a substrate by alternately performingfollowing steps prescribed number of times:

supplying one of the sources of a chlorosilane-based source and anaminosilane-based source to the substrate in a processing chamber, andthereafter supplying the other source, to form a first layer containingsilicon, nitrogen, and carbon on the substrate; and

supplying a reactive gas different from each of the sources, to thesubstrate in the processing chamber, to modify the first layer and forma second layer.

According to further other aspect of the present invention, there isprovided a substrate processing apparatus, including:

a processing chamber in which a substrate is housed;

a first source supply system configured to supply a chlorosilane-basedsource to a substrate in the processing chamber;

a second source supply system configured to supply an aminosilane-basedsource to the substrate in the processing chamber;

a reactive gas supply system configured to supply reactive gas differentfrom each of the sources, to the substrate in the processing chamber;and

a controller configured to control the first source supply system, thesecond source supply system, and the reactive gas supply system, so thatan insulating film having a prescribed composition and a prescribed filmthickness is formed on the substrate by alternately performing thefollowing processes prescribed number of times:

the process of supplying one of the sources of the chlorosilane-basedsource and the aminosilane-based source to the substrate in theprocessing chamber. and thereafter supplying the other source, to form afirst layer containing silicon, nitrogen, and carbon on the substrate,and

a process of supplying the reactive gas to the substrate in theprocessing chamber, to modify the first layer and form a second layer.

DESCRIPTION OF SIGNS AND NUMERALS

-   121 Controller-   200 Wafer-   201 Processing chamber-   202 Processing furnace-   203 Reaction tube-   207 Heater-   231 Exhaust tube-   232 a First gas supply tube-   232 b Second gas supply tube-   232 c Third gas supply tube-   232 d Fourth gas supply tube-   232 i Fifth gas supply tube-   232 j Sixth gas supply tube

1. A method for manufacturing a semiconductor device, comprising forming an insulating film having a prescribed composition and a prescribed film thickness on a substrate by alternately performing following steps prescribed number of times: supplying one of the sources of a chlorosilane-based source and an aminosilane-based source to a substrate in a processing chamber, and thereafter supplying the other source, to form a first layer containing silicon, nitrogen, and carbon on the substrate; and supplying a reactive gas different from each of the sources, to the substrate in the processing chamber, to modify the first layer and form a second layer.
 2. The method of claim 1, wherein in forming the second layer, thermally or plasma activated nitrogen-containing gas is supplied to the substrate as the reactive gas, to form a silicon carbonitride layer or a silicon nitride layer as the second layer, and in forming the insulating film, a silicon carbonitride film or a silicon nitride film is formed as the insulating film.
 3. The method of claim 1, wherein in forming the second layer, thermally activated nitrogen-containing gas is supplied to the substrate as the reactive gas, to form a silicon carbonitride layer as the second layer, and in forming the insulating film, a silicon carbonitride film is formed as the insulating film.
 4. The method of claim 1, wherein in forming the second layer, plasma activated nitrogen-containing gas is supplied to the substrate as the reactive gas, to form a silicon nitride layer as the second layer, and in forming the insulating film, a silicon nitride film is formed as the insulating film.
 5. The method of claim 1, wherein in forming the second layer, thermally activated carbon-containing gas is supplied to the substrate as the reactive gas, to form a silicon carbonitride layer as the second layer, and in forming the insulating film, a silicon carbonitride film is formed as the insulating film.
 6. The method of claim 1, wherein in forming the second layer, thermally or plasma-activated oxygen-containing gas is supplied to the substrate as the reactive gas, to form a silicon oxycarbonitride layer, a silicon oxycarbide layer, or a silicon oxide layer as the second layer, and in forming the insulating film, a silicon oxycarbonitride film, a silicon oxycarbide film, or a silicon oxide film is formed as the insulating film.
 7. The method of claim 1, wherein in forming the second layer, thermally activated oxygen-containing gas is supplied to the substrate as the reactive gas, to form a silicon oxycarbonitride layer or a silicon oxycarbide layer as the second layer, and in forming the insulating film, a silicon oxycarbonitride film or a silicon oxycarbide film is formed as the insulating film.
 8. The method of claim 1, wherein in forming the second layer, plasma activated oxygen-containing gas is supplied to the substrate as the reactive gas, to form a silicon oxide layer or a silicon oxycarbide layer as the second layer, and in forming the insulating film, a silicon oxide film or a silicon oxycarbide film is formed as the insulating film.
 9. The method of claim 1, wherein in forming the second layer, thermally activated boron-containing gas is supplied to the substrate as the reactive gas, to form a silicon boron carbonitride layer as the second layer, and in forming the insulating film, a silicon boron carbonitride film is formed as the insulating film.
 10. The method of claim 1, wherein in forming the second layer, thermally activated carbon-containing gas is supplied to the substrate as the reactive gas, and thereafter thermally activated nitrogen-containing gas is supplied to the substrate as the reactive gas, to form a silicon carbonitride layer as the second layer, and in forming the insulating film, a silicon carbonitride film is formed as the insulating film.
 11. The method of claim 1, wherein in forming the second layer, thermally activated carbon-containing gas is supplied to the substrate as the reactive gas, and thereafter thermally activated oxygen-containing gas is supplied to the substraet as the reactive gas, to form a silicon oxycarbonitride layer as the second layer, and in forming the insulating film, a silicon oxycarbonitride film is formed as the insulating film.
 12. The method of claim 1, wherein in forming the second layer, thermally activated boron-containing gas is supplied to the substrate as the reactive gas, and thereafter thermally activated nitrogen-containing gas is supplied to the substrate as the reactive gas, to form a silicon boron carbonitride layer as the second layer, and in forming the insulating film, a silicon boron carbonitride film is formed as the insulating film.
 13. The method of claim 1, wherein in forming the second layer, thermally activated nitrogen-containing gas is supplied to the substrate as the reactive gas, and thereafter thermally activated oxygen-containing gas is supplied to the substrate as the reactive gas, to form a silicon oxycarbonitride layer as the second layer, and in forming the insulating film, a silicon oxycarbonitride film is formed as the insulating film.
 14. The method of claim 1, wherein in forming the second layer, thermally activated carbon-containing gas is supplied to the substrate as the reactive gas, and thereafter thermally activated nitrogen-containing gas is supplied to the substrate as the reactive gas, and thereafter thermally activated oxygen-containing gas is supplied to the substrate as the reactive gas, to form a silicon oxycarbonitride layer as the second layer, and in forming the insulating film, a silicon oxycarbonitride film is formed as the insulating film.
 15. The method of claim 1, wherein in forming the second layer, thermally activated carbon-containing gas is supplied to the substrate as the reactive gas, and thereafter thermally activated boron-containing gas is supplied to the substrate as the reactive gas, and thereafter thermally activated nitrogen-containing gas is supplied to the substrate as the reactive gas, to form a silicon boron carbonitride layer as the second layer, and in forming the insulating film, a silicon boron carbonitride film is formed as the insulating film.
 16. A method for manufacturing a semiconductor device comprising: forming an insulating film having a prescribed composition and a prescribed film thickness on substrate by alternately performing following steps prescribed number of times: supplying a chlorosilane-based source and an aminosilane-based source to the substrate in a processing chamber, to form a first layer containing silicon, nitrogen, and carbon on the substrate; and supplying a reactive gas different from each of the sources, to the substrate in the processing chamber, to modify the first layer and form a second layer.
 17. A method for processing a substrate comprising: forming an insulating film having a prescribed composition and a prescribed film thickness on a substrate by alternately performing following steps prescribed number of times: supplying one of the sources of a chlorosilane-based source and an aminosilane-based source to the substrate in a processing chamber, and thereafter supplying the other source, to form a first layer containing silicon, nitrogen, and carbon on the substrate; and supplying a reactive gas different from each of the sources, to the substrate in the processing chamber, to modify the first layer and form a second layer.
 18. A substrate processing apparatus comprising: a processing chamber in which a substrate is housed; a first source supply system configured to supply a chlorosilane-based source to a substrate in the processing chamber; a second source supply system configured to supply an aminosilane-based source to the substrate in the processing chamber; a reactive gas supply system configured to supply a reactive gas different from each of the sources, to the substrate in the processing chamber; and a controller configured to control the first source supply system, the second source supply system, and the reactive gas supply system, so that an insulating film having a prescribed composition and a prescribed film thickness is formed on the substrate by alternately performing the following processes prescribed number of times: the process of supplying one of the sources of the chlorosilane-based source and the aminosilane-based source to the substrate in the processing chamber, and thereafter supplying the other source, to form a first layer containing silicon, nitrogen, and carbon on the substrate, and a process of supplying the reactive gas to the substrate in the processing chamber, to modify the first layer and form a second layer. 